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Jun 30, 2018
06/18

Jun 30, 2018
by
Sudipta Roy Barman; M. Maniraj; Abhishek Rai; Marian Krajčí; Pampa Sadhukhan; Vipin Kumar Singh; Katariina Pussi; Deborah L. Schlagel; Thomas A. Lograsso; Ajay Kumar Shukla

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Quasicrystalline materials exhibit aperiodic long range order and forbidden rotational symmetries, but show sharp diffraction spots. Although quasicrystals were discovered more than 30 years ago, elemental quasicrystals have remained elusive so far. Here, we demonstrate unique characteristics of an elemental Sn layer: it adopts a buckled five-fold quasiperiodic (QP) structure that is different from the icosahedral ($i$)-Al-Pd-Mn substrate. The pseudogap in the electronic states around the Fermi...

Topics: Materials Science, Condensed Matter, Other Condensed Matter

Source: http://arxiv.org/abs/1704.06783

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7.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Ren Bi; Zhongbo Yan; Ling Lu; Zhong Wang

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Topological nodal-line semimetals are characterized by one-dimensional lines of band crossing in the Brillouin zone. In contrast to nodal points, nodal lines can be in topologically nontrivial configurations. In this paper, we study the simplest topologically nontrivial forms of nodal line, namely, a single nodal line taking the shape of a knot in the Brillouin zone. We introduce a generic construction for various "nodal-knot semimetals", which yields the simplest trefoil nodal knot...

Topics: Quantum Gases, Condensed Matter, Strongly Correlated Electrons, Materials Science, Other Condensed...

Source: http://arxiv.org/abs/1704.06849

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5.0

Jun 30, 2018
06/18

Jun 30, 2018
by
M. Perarnau-Llobet; H. Wilming; A. Riera; R. Gallego; J. Eisert

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We derive general limitations concerning efficiency and power of heat engines strongly coupled to thermal baths. We build this framework on the insight that quantum systems strongly coupled to many-body systems will equilibrate to the reduced state of a global thermal state, deviating from the local thermal state of the system as it occurs in the weak-coupling limit. Taking this observation as the starting point of our analysis, we first provide strong-coupling corrections to the second law in...

Topics: Condensed Matter, Quantum Physics, Other Condensed Matter

Source: http://arxiv.org/abs/1704.05864

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5.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Pavel Lougovski; Nicholas A. Peters

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Silicon-based quantum logic is a promising technology to implement universal quantum computing. It is widely believed that a millikelvin cryogenic environment will be necessary to accommodate silicon-based qubits. This prompts a question of the ultimate scalability of the technology due to finite cooling capacity of refrigeration systems. In this work, we answer this question by studying energy dissipation due to interactions between nuclear spin impurities and qubit control pulses. We...

Topics: Condensed Matter, Quantum Physics, Other Condensed Matter

Source: http://arxiv.org/abs/1704.05504

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Jun 30, 2018
06/18

Jun 30, 2018
by
Julian Léonard; Andrea Morales; Philip Zupancic; Tobias Donner; Tilman Esslinger

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Access to collective excitations lies at the heart of our understanding of quantum many-body systems. We study the Higgs and Goldstone modes in a supersolid quantum gas that is created by coupling a Bose-Einstein condensate symmetrically to two optical cavities. The cavity fields form a U(1)-symmetric order parameter that can be modulated and monitored along both quadratures in real time. This enables us to measure the excitation energies across the superfluid-supersolid phase transition,...

Topics: Quantum Gases, Condensed Matter, Quantum Physics, Other Condensed Matter

Source: http://arxiv.org/abs/1704.05803

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6.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Z. Guguchia; F. v. Rohr; Z. Shermadini; A. T. Lee; S. Banerjee; A. R. Wieteska; C. A. Marianetti; H. Luetkens; Z. Gong; B. A. Frandsen; S. C. Cheung; C. Baines; A. Shengelaya; A. N. Pasupathy; E. Morenzoni; S. J. L. Billinge; A. Amato; R. J. Cava; R. Khasanov; Y. J. Uemura

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MoTe_2, with the orthorhombic T_d phase, is a new type (type-II) of Weyl semimetal, where the Weyl Fermions emerge at the boundary between electron and hole pockets. Non-saturating magnetoresistance (MR), and superconductivity were also observed in T_d-MoTe_2. Understanding the superconductivity in T_d-MoTe_2, which was proposed to be topologically non-trivial, is of eminent interest. Here, we report high-pressure (p_max = 1.3 GPa) muon spin rotation experiments on the temperature-dependent...

Topics: Materials Science, Condensed Matter, Superconductivity, Other Condensed Matter

Source: http://arxiv.org/abs/1704.05185

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4.0

Jun 30, 2018
06/18

Jun 30, 2018
by
S. Sharma; E. K. U. Gross; A. Sanna; J. K. Dewhurst

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Spin-dependent exchange-correlation energy functionals in use today depend on the charge density and the magnetization density: $E_{\rm xc}[\rho,{\bf m}]$. However, it is also correct to define the functional in terms of the curl of ${\bf m}$ for physical external fields: $E_{\rm xc}[\rho,\nabla\times{\bf m}]$. The exchange-correlation magnetic field, ${\bf B}_{\rm xc}$, then becomes source-free. We study this variation of the theory by uniquely removing the source term from local and...

Topics: Condensed Matter, Other Condensed Matter

Source: http://arxiv.org/abs/1704.04604

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4.0

Jun 30, 2018
06/18

Jun 30, 2018
by
T. J. S. Munsie; M. N. Wilson; A. Millington; C. M. Thompson; R. Flacau; C. Ding; Z. Gong; S. Guo; A. A. Aczel; H. B. Cao; T. J. Williams; H. A. Dabkowska; F. Ning; J. E. Greedan; G. M. Luke

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Neutron diffraction and muon spin relaxation ($\mu$SR) studies are presented for the newly characterized polymorph of NiNb$_2$O$_6$ ($\beta$-NiNb$_2$O$_6$) with space group P4$_2$/n and $\mu$SR data only for the previously known columbite structure polymorph with space group Pbcn. The magnetic structure of the P4$_2$/n form was determined from neutron diffraction using both powder and single crystal data. Powder neutron diffraction determined an ordering wave vector $\vec{k}$ =...

Topics: Condensed Matter, Other Condensed Matter

Source: http://arxiv.org/abs/1704.04043

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5.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Nicolas Höft; Jürgen Horbach; Victor Martin-Mayor; Beatriz Seoane

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We present a three-dimensional Ising model where lines of equal spins are frozen in such that they form an ordered framework structure. The frame spins impose an external field on the rest of the spins (active spins). We demonstrate that this "porous Ising model" can be seen as a minimal model for condensation transitions of gas molecules in metal-organic frameworks. Using Monte Carlo simulation techniques, we compare the phase behavior of a porous Ising model with that of a...

Topics: Materials Science, Condensed Matter, Other Condensed Matter

Source: http://arxiv.org/abs/1704.03233

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3.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Jingxi Luo; Bernard Piette

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We present a one-parameter family of mathematical models describing the dynamics of polarons in linear periodic structures such as polypeptides. By tuning the parameter, we are able to recover the Davydov and the Scott models. We describe the physical significance of this parameter. In the continuum limit, we derive analytical solutions which represent stationary polarons. On a discrete lattice, we compute stationary polaron solutions numerically. We investigate polaron propagation induced by...

Topics: Condensed Matter, Other Condensed Matter

Source: http://arxiv.org/abs/1704.02247

3
3.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Gavriil Shchedrin; David M. Lee

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Collective modes manifest themselves in a variety of different physical systems ranging from superconductors to superfluid $^{3}$He. The collective modes are generated via the Higgs-Anderson mechanism that is based on the symmetry breaking double well potential. Recently collective modes were explored in superconducting NbN and InO in the presence of a strong terahertz laser field. In both cases a single collective mode that oscillates with twice the frequency of the superconducting energy gap...

Topics: Condensed Matter, Superconductivity, Other Condensed Matter

Source: http://arxiv.org/abs/1704.02395

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8.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Mathias Boström; Oleksandr I. Malyi; Prachi Parashar; K. V. Shajesh; Priyadarshini Thiyam; Kimball A. Milton; Clas Persson; Drew F. Parsons; Iver Brevik

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At air-water interfaces, the Lifshitz interaction by itself does not promote ice growth. On the contrary, we find that the Lifshitz force promotes the growth of an ice film, up to 1-8 nm thickness, near silica-water interfaces at the triple point of water. This is achieved in a system where the combined effect of the retardation and the zero frequency mode influences the short-range interactions at low temperatures, contrary to common understanding. Cancellation between the positive and...

Topics: Condensed Matter, Other Condensed Matter, Soft Condensed Matter

Source: http://arxiv.org/abs/1704.01332

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8.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Seraph Bao; Silken Kleer; Ruoyu Wang; Armin Rahmani

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We apply the theory of optimal control to the dynamics of two "Gmon" qubits, with the goal of preparing a desired entangled ground state from an initial unentangled one. Given an initial state, a target state, and a Hamiltonian with a set of permissible controls, can we reach the target state with coherent quantum evolution and, in that case, what is the minimum time required? The adiabatic theorem provides a far from optimal solution in the presence of a spectral gap. Optimal control...

Topics: Condensed Matter, Quantum Physics, Other Condensed Matter

Source: http://arxiv.org/abs/1704.01423

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5.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Hualin Zhan; Jiri Cervenka; Steven Prawer; David J. Garrett

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The Hall resistance obtained in liquid gated Hall effect measurement of graphene demonstrates a higher sensitivity than the sheet resistance and the gate-source current for L-histidine of different concentrations in the pM range. This indicates that the extra information offered by the liquid gated Hall measurement of graphene can improve the sensitivity of the transistor-based potentiometric biosensors, and it could also be a supplementary method to the amperometric techniques for...

Topics: Mesoscale and Nanoscale Physics, Condensed Matter, Other Condensed Matter

Source: http://arxiv.org/abs/1704.01481

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7.0

Jun 30, 2018
06/18

Jun 30, 2018
by
J. Heckötter; M. Freitag; D. Fröhlich; M. Aßmann; M. Bayer; M. A. Semina; M. M. Glazov

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Rydberg atoms have attracted considerable interest due to their huge interaction among each other and with external fields. They demonstrate characteristic scaling laws in dependence on the principal quantum number $n$ for features such as the magnetic field for level crossing. While bearing striking similarities to Rydberg atoms, fundamentally new insights may be obtained for Rydberg excitons, as the crystal environment gives easy optical access to many states within an exciton multiplet. Here...

Topics: Materials Science, Condensed Matter, Mesoscale and Nanoscale Physics, Other Condensed Matter,...

Source: http://arxiv.org/abs/1704.00974

4
4.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Kapil Jainwal; Mukul Sarkar; Kushal Shah

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Randomization of the trap state of defects present at the gate Si-SiO$_2$ interface of MOSFET is responsible for the low-frequency noise phenomena such as Random Telegraph Signal (RTS), burst, and 1/\textit{f} noise. In a previous work, theoretical modelling and analysis of the RTS noise in MOS transistor was presented and it was shown that this 1/\textit{f} noise can be reduced by decreasing the duty cycle ($f_{D}$) of switched biasing signal. In this paper, an extended analysis of this...

Topics: Condensed Matter, Other Condensed Matter

Source: http://arxiv.org/abs/1704.00876

7
7.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Hiromitsu Takeuchi

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The domain-area distribution in the phase transition dynamics of $Z_2$ symmetry breaking is studied for quasi-two-dimensional multi-component superfluids. The distribution is divided into microscopic and macroscopic regimes with distinct power-law exponents. The macroscopic regime universally exhibits Fischer's law in percolation theory, while the microscopic regime depends on the microscopic dynamics of the system. Numerical experiments of segregating superfluids reveal that the exponent in...

Topics: Quantum Gases, Condensed Matter, Nonlinear Sciences, Pattern Formation and Solitons, Statistical...

Source: http://arxiv.org/abs/1703.10581

4
4.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Seyyed M. H. Halataei

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I present the exact solution of a toy model for gravitationally induced decoherence. The toy model has Hamiltonian resembling optomechanical systems. It is an oscillator system coupled through its energy to an oscillator heat bath. I find the decoherence effect of vacuum fluctuations at zero temperature. Also for a finite bath I show that the decoherence is in general present and the system does not return to its initial coherence unless the fundamental frequencies of the bath have rational...

Topics: Optics, Condensed Matter, Quantum Physics, Other Condensed Matter, Physics

Source: http://arxiv.org/abs/1703.10687

4
4.0

Jun 30, 2018
06/18

Jun 30, 2018
by
P. S. Vinayagam; R. Radha; S. Bhuvaneswari; R. Ravisankar; P. Muruganandam

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We investigate the dynamics of a spin-orbit (SO) coupled BECs in a time dependent harmonic trap and show the dynamical system to be completely integrable by constructing the Lax pair. We then employ gauge transformation approach to witness the rapid oscillations of the condensates for a relatively smaller value of SO coupling in a time independent harmonic trap compared to their counterparts in a transient trap. Keeping track of the evolution of the condensates in a transient trap during its...

Topics: Quantum Gases, Condensed Matter, Other Condensed Matter

Source: http://arxiv.org/abs/1703.09119

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3.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Fábio Barachati; Janos Simon; Yulia A. Getmanenko; Seth R. Marder; Stéphane Kéna-Cohen

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Strong inter-particle interactions between polaritons have traditionally stemmed from their exciton component. In this work, we impart a strong photonic nonlinearity to a polaritonic mode by embedding a nonlinear polymethine dye within a high-Q all-metal microcavity. We demonstrate nonlinear microcavities operating in the ultrastrong coupling regime with a normalized coupling ratio of 62\%, the highest reported to date. When pumping the lower polariton branch, we observe tunable third-harmonic...

Topics: Quantum Gases, Condensed Matter, Optics, Other Condensed Matter, Physics

Source: http://arxiv.org/abs/1703.08536

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7.0

Jun 30, 2018
06/18

Jun 30, 2018
by
S. Karmakar; M. Schaber; A. -L. Schuhmacher; M. Scheel; M. DiMichiel; M. Brinkmann; R. Seemann; L. Kovalcinova; L. Kondic

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Energy dissipation in sheared dry and wet granulates is explored experimentally and computationally as a function of confining pressure $P_{\rm cf}$. For vanishing confining pressure, $P_{\rm cf} \rightarrow 0$, the energy dissipation fades in the case of dry granulates. In the case of wet granulates, a finite energy dissipation for $P_{\rm cf} \rightarrow 0$ is observed and explained quantitatively by a combination of two effects related to capillary forces: frictional resistance of the...

Topics: Physics, Condensed Matter, Soft Condensed Matter, Other Condensed Matter, Computational Physics

Source: http://arxiv.org/abs/1703.08523

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8.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Jorge Cuadra; Denis G. Baranov; Martin Wersäll; Ruggero Verre; Tomasz J. Antosiewicz; Timur Shegai

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Formation of dressed light-matter states in optical structures, manifested as Rabi splitting of the eigen energies of a coupled system, is one of the key effects in quantum optics. In pursuing this regime with semiconductors, light is usually made to interact with excitons $-$ electrically neutral quasiparticles of semiconductors, meanwhile interactions with charged three-particle states $-$ trions $-$ have received little attention. Here, we report on strong interaction between plasmons in...

Topics: Optics, Physics, Condensed Matter, Other Condensed Matter

Source: http://arxiv.org/abs/1703.07873

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10.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Alexander Karabanov; Dominic C. Rose; Walter Köckenberger; Juan P. Garrahan; Igor Lesanovsky

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We study an ensemble of strongly coupled electrons under continuous microwave irradiation interacting with a dissipative environment, a problem of relevance to the creation of highly polarized non-equilibrium states in nuclear magnetic resonance. We analyse the stationary states of the dynamics, described within a Lindblad master equation framework, at the mean-field approximation level. This approach allows us to identify steady state phase transitions between phases of high and low...

Topics: Statistical Mechanics, Condensed Matter, Other Condensed Matter, Quantum Physics

Source: http://arxiv.org/abs/1703.07159

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4.0

Jun 30, 2018
06/18

Jun 30, 2018
by
J. Krausser; A. Lagogianni; K. Samwer; A. Zaccone

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Within the shoving model of the glass transition, the relaxation time and the viscosity are related to the local cage rigidity. This approach can be extended down to the atomic-level in terms of the interatomic interaction, or potential of mean-force. We applied this approach to both real metallic glass-formers and model Lennard-Jones glasses. The main outcome of this analysis is that in metallic glasses the thermal expansion contribution is mostly independent of composition and is uncorrelated...

Topics: Materials Science, Condensed Matter, Soft Condensed Matter, Other Condensed Matter

Source: http://arxiv.org/abs/1703.06457

4
4.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Manfred Fähnle

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Recently the spectacular result was derived quantum mechanically that the total angular momentum of photons in light beams with finite lateral extensions can have half-integer quantum numbers. In a circularly polarized Gauss light beam it is half of the spin angular momentum which it would have in a respective infinitely extended wave. In another paper it was shown by a classical calculation that the magnetic moment induced by such a beam in a metal is a factor of two smaller than the one...

Topics: Optics, Condensed Matter, Physics, Other Condensed Matter

Source: http://arxiv.org/abs/1703.05821

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4.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Alex J. Kruchkov; J. S. White; M. Bartowiak; I. Zivcovic; A. Magrez; H. M. Rønnow

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Magnetic skyrmions are topologically protected spin-whirl quasiparticles currently considered as promising components for ultra-dense memory devices. In the bulk they form lattices that are stable over just a few Kelvin below the ordering temperature. This narrow stability range presents a key challenge for applications, and finding ways to tune the SkL stability over a wider phase space is a pressing issue. Here we show experimentally that the skyrmion phase in the magnetoelectric insulator...

Topics: Condensed Matter, Mesoscale and Nanoscale Physics, Other Condensed Matter

Source: http://arxiv.org/abs/1703.06081

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3.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Okan K. Orhan; David D. O'Regan

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We develop a generalization of the density functional theory + Hubbard $U$ (DFT+$U$) method to the excited-state regime, in the form of Hubbard $U$ corrected linear-response time-dependent DFT or 'TDDFT+$U$'. Combined with calculated linear-response Hubbard $U$ parameters, this represents a computationally light, first-principles method for the simulation of tightly-bound excitons on transition-metal ions and more generally. In detailed calculations on closed-shell nickel coordination...

Topics: Physics, Condensed Matter, Chemical Physics, Strongly Correlated Electrons, Other Condensed Matter,...

Source: http://arxiv.org/abs/1703.05056

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6.0

Jun 30, 2018
06/18

Jun 30, 2018
by
P. M. Walmsley; A. I. Golov

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Tangles of quantized vortex line of initial density ${\cal L}(0) \sim 6\times 10^3$\,cm$^{-2}$ and variable amplitude of fluctuations of flow velocity $U(0)$ at the largest length scale were generated in superfluid $^4$He at $T=0.17$\,K, and their free decay ${\cal L}(t)$ was measured. If $U(0)$ is small, the excess random component of vortex line length firstly decays as ${\cal L} \propto t^{-1}$ until it becomes comparable with the structured component responsible for the classical velocity...

Topics: Fluid Dynamics, Physics, Condensed Matter, Other Condensed Matter

Source: http://arxiv.org/abs/1703.03645

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8.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Sophia R. Sklan; Baowen Li

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The advances in geometric approaches to optical devices due to transformation optics has led to the development of cloaks, concentrators, and other devices. It has also been shown that transformation optics can be used to gravitational fields from general relativity. However, the technique is currently constrained to linear devices, as a consistent approach to nonlinearity (including both the case of a nonlinear background medium and a nonlinear transformation) remains an open question. Here we...

Topics: General Relativity and Quantum Cosmology, Physics, Condensed Matter, Nonlinear Sciences, Other...

Source: http://arxiv.org/abs/1703.03458

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6.0

Jun 30, 2018
06/18

Jun 30, 2018
by
M. Gluza; M. Kliesch; J. Eisert; L. Aolita

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The experimental interest in realizing quantum spin-1/2-chains has increased uninterruptedly over the last decade. In many instances, the target quantum simulation belongs to the broader class of non-interacting fermionic models, constituting an important benchmark. In spite of this class being analytically efficiently tractable, no direct certification tool has yet been reported for it. In fact, in experiments, certification has almost exclusively relied on notions of quantum state tomography...

Topics: Condensed Matter, Quantum Physics, Other Condensed Matter

Source: http://arxiv.org/abs/1703.03152

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3.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Timothy R. Prisk; Matthew S. Bryan; Paul. E. Sokol; Garrett E. Granroth; Saverio Moroni; Massimo Boninsegni

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We report high-resolution neutron Compton scattering measurements of liquid $^4$He under saturated vapor pressure. There is excellent agreement between the observed scattering and ab initio predictions of its lineshape. Quantum Monte Carlo calculations predict that the Bose condensate fraction is zero in the normal fluid, builds up rapidly just below the superfluid transition temperature, and reaches a value of approximately $7.5\%$ below 1 K. We also used model fit functions to obtain from the...

Topics: Condensed Matter, Other Condensed Matter

Source: http://arxiv.org/abs/1703.03018

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Jun 30, 2018
06/18

Jun 30, 2018
by
A. Gianfrate; L. Dominici; O. Voronych; M. Matuszewski; M. Stobińska; D. Ballarini; M. De Giorgi; G. Gigli; D. Sanvitto

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In this work we experimentally demonstrate the generation of exciton-polariton X-waves and study their dynamics in time. X-waves belong to the category of localized packets, a class of states able to sustain their shape without the need of any nonlinearity. This allows to keep the packet shape for very low densities and very long times compared, for instance, to soliton waves which, on the contrary, always need nonlinearity to compensate the diffusion. The use of polaritons in microcavities is...

Topics: Quantum Gases, Condensed Matter, Physics, Fluid Dynamics, Nonlinear Sciences, Pattern Formation and...

Source: http://arxiv.org/abs/1703.02313

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3.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Prafulla Oak; B. Sathiapalan

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The exact renormalization group is used to study the RG flow of quantities in field theories. The basic idea is to write an evolution operator for the flow and evaluate it in perturbation theory. This is easier than directly solving the differential equation. This is illustrated by reproducing known results in four dimensional $\phi^4$ field theory and the two dimensional Sine-Gordon theory. It is shown that the calculation of beta function is somewhat simplified. The technique is also used to...

Topics: High Energy Physics - Theory, Condensed Matter, Other Condensed Matter

Source: http://arxiv.org/abs/1703.01591

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4.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Tetsuo Hatakeyama; Yuji Kiuchi; Mitsuru Sometani; Shinsuke Harada; Dai Okamoto; Hiroshi Yano; Yoshiyuki Yonezawa; Hajime Okumura

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The effects of nitridation on the density of traps at SiO$_2$/SiC interfaces near the conduction band edge were qualitatively examined by a simple, newly developed characterization method that utilizes Hall effect measurements and split capacitance-voltage measurements. The results showed a significant reduction in the density of interface traps near the conduction band edge by nitridation, as well as the high density of interface traps that was not eliminated by nitridation.

Topics: Materials Science, Condensed Matter, Other Condensed Matter

Source: http://arxiv.org/abs/1703.00615

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3.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Giuseppe M. J. Barca; Pierre-François Loos

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In the spirit of the Head-Gordon-Pople algorithm, we report vertical, transfer and horizontal recurrence relations for the efficient and accurate computation of four-electron integrals over Gaussian basis functions. Our recursive approach is a generalization of our algorithm for three-electron integrals [J.~Chem.~Theory Comput.~12, 1735 (2016)]. The RRs derived in the present study can be applied to a general class of multiplicative four-electron operators. In particular, we consider various...

Topics: Physics, Condensed Matter, Chemical Physics, Strongly Correlated Electrons, Other Condensed Matter,...

Source: http://arxiv.org/abs/1703.00846

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Jun 30, 2018
06/18

Jun 30, 2018
by
L. V. Abdurakhimov; M. A. Borich; Yu. M. Bunkov; R. R. Gazizulin; D. Konstantinov; M. I. Kurkin; A. P. Tankeyev

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We present a new theoretical description of the coupled electron-nuclear spin systems which takes into account an indirect relaxation of nuclear spins via the electron subsystem. In our theory the magnitude of the nuclear magnetization is conserved for arbitrary large excitation powers, similar to the Landau-Lifshitz-Gilbert model of relaxation. This is drastically different from the conventional heating scenario based on the phenomenological Bloch equations. The predictions of our theory are...

Topics: Condensed Matter, Other Condensed Matter

Source: http://arxiv.org/abs/1703.00614

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6.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Gabriel Menezes; Claus Kiefer; Jamir Marino

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We study the Casimir-Polder force arising between two identical two-level atoms and mediated by a massless scalar field propagating in a black-hole background. We study the interplay of Hawking radiation and Casimir-Polder forces and find that, when the atoms are placed near the event horizon, the scaling of the Casimir-Polder interaction energy as a function of interatomic distance displays a transition from a thermallike character to a nonthermal behavior. We corroborate our findings for a...

Topics: General Relativity and Quantum Cosmology, Condensed Matter, Quantum Physics, Other Condensed Matter

Source: http://arxiv.org/abs/1703.00193

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Jun 30, 2018
06/18

Jun 30, 2018
by
Alex J. Kruchkov; Henrik M. Rønnow

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This paper studies the influence of electric fields on the skyrmion lattice (SkL) in insulating skyrmion compounds with weak magnetoelectric (ME) coupling. The ME coupling mechanism is an interaction between the external electric field $E$ and local magnetization in the sample. Physically, the $E$-field perturbs the spin modulation wave vectors resulting in the distortion of the SkL and the $E$-field induced shift in energy. Due to the relativistic smallness of ME coupling, the important...

Topics: Condensed Matter, Other Condensed Matter

Source: http://arxiv.org/abs/1702.08863

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Jun 30, 2018
06/18

Jun 30, 2018
by
Naoki Yamamoto

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Circularly polarized photons have the Berry curvature in the semiclassical regime. Based on the kinetic equation for such chiral photons, we derive the (non)equilibrium expression of the photon current in the direction of the vorticity. We briefly discuss the relevance of this "photonic chiral vortical effect" in pulsars and rotating massive stars and its possible realization in semiconductors.

Topics: Physics, Condensed Matter, Astrophysics, High Energy Astrophysical Phenomena, Other Condensed...

Source: http://arxiv.org/abs/1702.08886

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Jun 30, 2018
06/18

Jun 30, 2018
by
Ádám Butykai; Sándor Bordács; István Kézsmárki; Vladimir Tsurkan; Alois Loidl; Jonathan Döring; Peter Milde; Susanne C. Kehr; Lukas M. Eng

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GaV$_4$S$_8$ is a multiferroic semiconductor hosting N{\'e}el-type magnetic skyrmions dressed with electric polarization. At T$_s$ = 42K, the compound undergoes a structural phase transition of weakly first-order, from a non-centrosymmetric cubic phase at high temperatures to a polar rhombohedral structure at low temperatures. Below T$_s$, ferroelectric domains are formed with the electric polarization pointing along any of the four $\left < 111 \right>$ axes. Although in this material...

Topics: Materials Science, Condensed Matter, Other Condensed Matter

Source: http://arxiv.org/abs/1702.07245

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Jun 30, 2018
06/18

Jun 30, 2018
by
Vladislav S. Yakovlev; Michael S. Wismer

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We show how to significantly reduce the number of energy bands required to model the interaction of light with crystalline solids in the velocity gauge. We achieve this by deriving analytical corrections to the electric current density. These corrections depend only on band energies, the matrix elements of the momentum operator, and the macroscopic vector potential. Thus, the corrections can be evaluated independently from modeling the interaction with light. In addition to improving the...

Topics: Physics, Condensed Matter, Computational Physics, Other Condensed Matter

Source: http://arxiv.org/abs/1702.07410

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3.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Shawn X. Cui; Zhenghan Wang

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We define a family of quantum invariants of closed oriented $3$-manifolds using spherical multi-fusion categories. The state sum nature of this invariant leads directly to $(2+1)$-dimensional topological quantum field theories ($\text{TQFT}$s), which generalize the Turaev-Viro-Barrett-Westbury ($\text{TVBW}$) $\text{TQFT}$s from spherical fusion categories. The invariant is given as a state sum over labeled triangulations, which is mostly parallel to, but richer than the $\text{TVBW}$ approach...

Topics: Condensed Matter, Mathematical Physics, Category Theory, Quantum Algebra, Other Condensed Matter,...

Source: http://arxiv.org/abs/1702.07113

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Jun 30, 2018
06/18

Jun 30, 2018
by
Robbert-Jan Dikken

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A model is developed describing the energy distribution of quasi-particles in a quasi-one dimensional, normal metal wire, where the transport is diffusive, connected between equilibrium reservoirs. When an ac bias is applied to the wire by means of the reservoirs, the statistics of the charge carriers is influence by the formed non-equilibrium. The proposed model is derived from Green function formalism. The quasi-particle energy distribution is calculated with a quantum diffusion equation...

Topics: Mesoscale and Nanoscale Physics, Condensed Matter, Other Condensed Matter, Quantum Physics

Source: http://arxiv.org/abs/1702.05408

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Jun 30, 2018
06/18

Jun 30, 2018
by
Raphaël Gervais Lavoie; Mathieu Ouellet; Jean Hamelin; Pierre Bénard

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In this paper, we present a detailed numerical implementation of the multicomponent potential theory of adsorption which is among the most accurate gas mixtures adsorption models. The implementation uses the NIST Refprop database to describe fluid properties and applies to pure gases and mixtures in both subcritical and supercritical regimes. The limitations of the model and the issues encountered with its implementation are discussed. The adsorption isotherms of CH4 / CO2 mixture are modeled...

Topics: Physics, Condensed Matter, Other Condensed Matter, Chemical Physics

Source: http://arxiv.org/abs/1702.05401

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Jun 30, 2018
06/18

Jun 30, 2018
by
M Ruminy; S Chi; S Calder; T Fennell

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To understand emergent magnetic monopole dynamics in the spin ices Ho$_2$Ti$_2$O$_7$ and Dy$_2$Ti$_2$O$_7$, it is necessary to investigate the mechanisms by which spins flip in these materials. Presently there are thought to be two processes: quantum tunneling at low and intermediate temperatures and thermally activated at high temperatures. We identify possible couplings between crystal field and optical phonon excitations and construct a strictly constrained model of phonon-mediated spin...

Topics: Strongly Correlated Electrons, Condensed Matter, Other Condensed Matter

Source: http://arxiv.org/abs/1702.04612

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Jun 30, 2018
06/18

Jun 30, 2018
by
Diana Prychynenko; Matthias Sitte; Kai Litzius; Benjamin Krüger; George Bourianoff; Mathias Kläui; Jairo Sinova; Karin Everschor-Sitte

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Inspired by the human brain, there is a strong effort to find alternative models of information processing capable of imitating the high energy efficiency of neuromorphic information processing. One possible realization of cognitive computing are reservoir computing networks. These networks are built out of non-linear resistive elements which are recursively connected. We propose that a skyrmion network embedded in frustrated magnetic films may provide a suitable physical implementation for...

Topics: Strongly Correlated Electrons, Disordered Systems and Neural Networks, Condensed Matter, Other...

Source: http://arxiv.org/abs/1702.04298

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Jun 30, 2018
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Jun 30, 2018
by
S. Azaizia; H. Carrère; J. C. Sandoval-Santana; V. G. Ibarra-Sierra; V. K. Kalevich; E. L. Ivchenko; L. A. Bakaleinikov; X. Marie; T. Amand; A. Kunold; A. Balocchi

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We demonstrate the detection of coherent electron-nuclear spin oscillations related to the hyperfine interaction and revealed by the band-to-band photoluminescence (PL) in zero external magnetic field. On the base of a pump-probe PL experiment we measure, directly in the temporal domain, the hyperfine constant of an electron coupled to a gallium defect in GaAsN by tracing the dynamical behavior of the conduction electron spin-dependent recombination to the defect site. The hyperfine constants...

Topics: Mesoscale and Nanoscale Physics, Condensed Matter, Other Condensed Matter

Source: http://arxiv.org/abs/1702.04129

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Jun 30, 2018
06/18

Jun 30, 2018
by
S. Śmiga; E. Fabiano; L. A. Constantin; F. Della Sala

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The development of semilocal models for the kinetic energy density (KED) is an important topic in density functional theory (DFT). This is especially true for subsystem DFT, where these models are necessary to construct the required non-additive embedding contributions. In particular, these models can also be efficiently employed to replace the exact KED in meta-Generalized Gradient Approximation (meta-GGA) exchange-correlation functionals allowing to extend the subsystem DFT applicability to...

Topics: Physics, Condensed Matter, Other Condensed Matter, Chemical Physics

Source: http://arxiv.org/abs/1702.04154

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4.0

Jun 30, 2018
06/18

Jun 30, 2018
by
Maksim Tomchenko

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A general method of description of a spontaneously polarized isotropic dielectric is constructed. It is based on the Maxwell equations for a medium and on the statistical averaging of the sources of spontaneous polarization (dipoles or multipoles). We show that the sources of spontaneous polarization in the Maxwell equations should be considered as conditionally foreign charges. In the literature, two basic approaches to the description of spontaneously polarized He II are available:...

Topics: Physics, Condensed Matter, Other Condensed Matter, Classical Physics

Source: http://arxiv.org/abs/1702.04290

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Jun 30, 2018
06/18

Jun 30, 2018
by
Nikolai A. Zarkevich; D. D. Johnson

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FeRh is a showcase for caloric materials genome, transforming upon heating from the type-2 antiferromagnet (AFM) to a ferromagnet (FM). FeRh AFM (but not FM) cubic B2 lattice is unstable at ambient pressure. We describe the stable orthorhombic AFM FeRh structure at low temperature T. We claim that the austenitic AFM B2 phase has a premartensitic instability at room T, and it must transform to a martensite at cryogenic T below 23K. We also address the metamagnetic phase transformation at 353K...

Topics: Physics, Condensed Matter, Chemical Physics, Materials Science, Other Condensed Matter,...

Source: http://arxiv.org/abs/1702.03042