American Institute of Physics: Low Temperature Physics: Table of Contents
Table of Contents for Low Temperature Physics. List of articles from both the latest and ahead of print issues.
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American Institute of Physics: Low Temperature Physics: Table of Contents
American Institute of Physics
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Low Temperature Physics
https://aip.scitation.org/na101/home/literatum/publisher/aip/journals/content/ltp/2022/ltp.2022.48.issue5/ltp.2022.48.issue5/2022051101/ltp.2022.48.issue5.cover.jpg
https://aip.scitation.org/loi/ltp?af=R&feed=mostrecent

Mark Yakovlevich Azbel (May 12, 1932–March 31, 2020)
https://aip.scitation.org/doi/10.1063/10.0010198?af=R&feed=mostrecent
Low Temperature Physics, <a href="https://aip.scitation.org/toc/ltp/48/5">Volume 48, Issue 5</a>, Page 359362, May 2022. <br/>
Low Temperature Physics, Volume 48, Issue 5, Page 359362, May 2022. <br/>
Mark Yakovlevich Azbel (May 12, 1932–March 31, 2020)
10.1063/10.0010198
Low Temperature Physics
20220511T03:45:05Z
© 2022 Author(s).
S. A. Gredeskul
L. A. Pastur
Yu. A. Freiman
V. M. Kontorovich
V. G. Peschansky

Slow oscillating dynamics of a twolevel system subject to a fast telegraph noise: Beyond the NIBA approximation
https://aip.scitation.org/doi/10.1063/10.0010199?af=R&feed=mostrecent
Low Temperature Physics, <a href="https://aip.scitation.org/toc/ltp/48/5">Volume 48, Issue 5</a>, Page 363370, May 2022. <br/>We study the dynamics of a twosite model in which the tunneling amplitude between the sites is not constant, but rather a highfrequency noise. Obviously, the population imbalance in this model decays exponentially with time. Remarkably, the decay is modified dramatically when the level asymmetry fluctuates inphase with fluctuations of the tunneling amplitude. For a particular type of these inphase fluctuations, namely, the telegraph noise, we find the exact solution for the average population dynamics. It appears that the population imbalance between the sites starting from 1 at time t = 0 approaches a constant value in the limit [math]. At finite bias, the imbalance goes to zero at [math], while the dynamics of the decay governed by noise acquires an oscillatory character.
Low Temperature Physics, Volume 48, Issue 5, Page 363370, May 2022. <br/>We study the dynamics of a twosite model in which the tunneling amplitude between the sites is not constant, but rather a highfrequency noise. Obviously, the population imbalance in this model decays exponentially with time. Remarkably, the decay is modified dramatically when the level asymmetry fluctuates inphase with fluctuations of the tunneling amplitude. For a particular type of these inphase fluctuations, namely, the telegraph noise, we find the exact solution for the average population dynamics. It appears that the population imbalance between the sites starting from 1 at time t = 0 approaches a constant value in the limit [math]. At finite bias, the imbalance goes to zero at [math], while the dynamics of the decay governed by noise acquires an oscillatory character.
Slow oscillating dynamics of a twolevel system subject to a fast telegraph noise: Beyond the NIBA approximation
10.1063/10.0010199
Low Temperature Physics
20220511T03:45:05Z
© 2022 Author(s).
V. V. Mkhitaryan
M. E. Raikh

On the theory of nonhomogeneous nonequilibrium superconductivity in 2D systems with massless fermions
https://aip.scitation.org/doi/10.1063/10.0010200?af=R&feed=mostrecent
Low Temperature Physics, <a href="https://aip.scitation.org/toc/ltp/48/5">Volume 48, Issue 5</a>, Page 371377, May 2022. <br/>We analyze static and nonequilibrium superconducting properties of a 2D relativisticlike model system with local electronelectron interaction, Rashba spinorbit interaction αR in presence of timedependent inplane magnetic field H(t). It is shown that similar to the 2D case with ordinary massive quasiparticle dispersion [math] at large fields, such a system demonstrates a nonhomogeneous superconducting stripe phase with the order parameter [math] (B is the magnetic induction, υF is the Fermi velocity, n is the normal to the plane, μB is the Bohr magneton, and [math]) where the stripes are oriented along the B direction. In the considered system, the interstripe period L and the magnitude of the magnetic field B are related by a universal relation [math]. Contrary to the case of massive quasiparticles, where the condition [math] can be, in principle, satisfied by increasing αR or by charge doping (Fermi velocity decreasing), in a relativisticlike system, where υF is dopingindependent and onetwo orders of magnitude larger than typical Fermi velocity in the “standard” 2D systems, the stripe phase can be the ground state at a rather low doping level. We also analyzed the nonequilibrium properties of the system with a focus on the melting of the stripe order (when the magnetic field is quenched to a lower value) and stripe dynamics (when the field is rotated by 90° degrees) and found several notable results. In particular, it was shown that the stripe domains melt according to law [math] at initial times, while at longer times they shrink exponentially. In the case of the flipped magnetic field, the stripe orientation gradually turns from x to ydirection, and the intermediate “crossedstripe” phase takes place during times of order of picoseconds. Such a crossed phase is built of periodic superconducting bubbles that potentially may have applications in modern ultrafast superconducting technologies.
Low Temperature Physics, Volume 48, Issue 5, Page 371377, May 2022. <br/>We analyze static and nonequilibrium superconducting properties of a 2D relativisticlike model system with local electronelectron interaction, Rashba spinorbit interaction αR in presence of timedependent inplane magnetic field H(t). It is shown that similar to the 2D case with ordinary massive quasiparticle dispersion [math] at large fields, such a system demonstrates a nonhomogeneous superconducting stripe phase with the order parameter [math] (B is the magnetic induction, υF is the Fermi velocity, n is the normal to the plane, μB is the Bohr magneton, and [math]) where the stripes are oriented along the B direction. In the considered system, the interstripe period L and the magnitude of the magnetic field B are related by a universal relation [math]. Contrary to the case of massive quasiparticles, where the condition [math] can be, in principle, satisfied by increasing αR or by charge doping (Fermi velocity decreasing), in a relativisticlike system, where υF is dopingindependent and onetwo orders of magnitude larger than typical Fermi velocity in the “standard” 2D systems, the stripe phase can be the ground state at a rather low doping level. We also analyzed the nonequilibrium properties of the system with a focus on the melting of the stripe order (when the magnetic field is quenched to a lower value) and stripe dynamics (when the field is rotated by 90° degrees) and found several notable results. In particular, it was shown that the stripe domains melt according to law [math] at initial times, while at longer times they shrink exponentially. In the case of the flipped magnetic field, the stripe orientation gradually turns from x to ydirection, and the intermediate “crossedstripe” phase takes place during times of order of picoseconds. Such a crossed phase is built of periodic superconducting bubbles that potentially may have applications in modern ultrafast superconducting technologies.
On the theory of nonhomogeneous nonequilibrium superconductivity in 2D systems with massless fermions
10.1063/10.0010200
Low Temperature Physics
20220511T03:45:07Z
© 2022 Author(s).
V. M. Loktev
V. Turkowski

Perspectives in cosmology
https://aip.scitation.org/doi/10.1063/10.0010201?af=R&feed=mostrecent
Low Temperature Physics, <a href="https://aip.scitation.org/toc/ltp/48/5">Volume 48, Issue 5</a>, Page 378382, May 2022. <br/>The “new standard cosmology,” based on the theory of inflation, has very impressive observational support. I review some outstanding problems of the new cosmology and the global view of the universe—the multiverse—that it suggests.
Low Temperature Physics, Volume 48, Issue 5, Page 378382, May 2022. <br/>The “new standard cosmology,” based on the theory of inflation, has very impressive observational support. I review some outstanding problems of the new cosmology and the global view of the universe—the multiverse—that it suggests.
Perspectives in cosmology
10.1063/10.0010201
Low Temperature Physics
20220511T03:45:06Z
© 2022 Author(s).
Alexander Vilenkin

Ground state of the biaxial spin1/2 open chain
https://aip.scitation.org/doi/10.1063/10.0010202?af=R&feed=mostrecent
Low Temperature Physics, <a href="https://aip.scitation.org/toc/ltp/48/5">Volume 48, Issue 5</a>, Page 383388, May 2022. <br/>The ground state behavior of the biaxial spin1/2 chain with free open edges is studied. Using the exact Bethe ansatz solution we show that there can exist boundary bound states for many finite values of the exchange coupling constants. The nontrivial interaction between spins produces charging of the vacua of the model and boundary bound states. Our theory also describes the behavior of the spinless fermion chain with pairing (the Kitaev chain) and an interaction between fermions at neighboring sites for free open boundaries. Therefore, the simple case of noninteracting fermions simplest boundary states are Majorana edge modes.
Low Temperature Physics, Volume 48, Issue 5, Page 383388, May 2022. <br/>The ground state behavior of the biaxial spin1/2 chain with free open edges is studied. Using the exact Bethe ansatz solution we show that there can exist boundary bound states for many finite values of the exchange coupling constants. The nontrivial interaction between spins produces charging of the vacua of the model and boundary bound states. Our theory also describes the behavior of the spinless fermion chain with pairing (the Kitaev chain) and an interaction between fermions at neighboring sites for free open boundaries. Therefore, the simple case of noninteracting fermions simplest boundary states are Majorana edge modes.
Ground state of the biaxial spin1/2 open chain
10.1063/10.0010202
Low Temperature Physics
20220511T03:45:06Z
© 2022 Author(s).
A. A. Zvyagin

Resonant tunneling and bound states in the continuum
https://aip.scitation.org/doi/10.1063/10.0010203?af=R&feed=mostrecent
Low Temperature Physics, <a href="https://aip.scitation.org/toc/ltp/48/5">Volume 48, Issue 5</a>, Page 389395, May 2022. <br/>Many research topics these days involve the study of resonances in different structured media, especially in the field of optics. The seemingly different discovery of cyclotron resonance in metals by Azbel and Kaner in 1956 {Zh. Eksp. Teor. Fiz. 30, 811 (1956) [Sov. Phys. JETP 3, 772 (1956)]} that opened a new way to study the Fermi surface of metals has never been linked to optics. However, some later works of Azbel on resonant tunneling are closely related to the concepts currently developing in optics and photonics, and here I discuss some of those fundamental ideas underpinned by the physics of Fano resonances and bound states in the continuum with a few examples of their experimental demonstrations.
Low Temperature Physics, Volume 48, Issue 5, Page 389395, May 2022. <br/>Many research topics these days involve the study of resonances in different structured media, especially in the field of optics. The seemingly different discovery of cyclotron resonance in metals by Azbel and Kaner in 1956 {Zh. Eksp. Teor. Fiz. 30, 811 (1956) [Sov. Phys. JETP 3, 772 (1956)]} that opened a new way to study the Fermi surface of metals has never been linked to optics. However, some later works of Azbel on resonant tunneling are closely related to the concepts currently developing in optics and photonics, and here I discuss some of those fundamental ideas underpinned by the physics of Fano resonances and bound states in the continuum with a few examples of their experimental demonstrations.
Resonant tunneling and bound states in the continuum
10.1063/10.0010203
Low Temperature Physics
20220511T03:45:06Z
© 2022 Author(s).
Yuri Kivshar

The link between Fisher information and geometric discord
https://aip.scitation.org/doi/10.1063/10.0010204?af=R&feed=mostrecent
Low Temperature Physics, <a href="https://aip.scitation.org/toc/ltp/48/5">Volume 48, Issue 5</a>, Page 396399, May 2022. <br/>By considering an arbitrary twoqubit state, it is shown that the Fisher information is intrinsically linked to the geometric discord which allows a measure for quantum correlations beyond entanglement. The complex amplitude of oscillations of the probability density function is upper bounded by the geometric discord which subsequently results in the Fisher information being bounded by the geometric discord. This gives an experimental observable which can be used to quantify quantum correlations beyond entanglement. This observable can be used to witness quantum correlations in an interferometry experiment, and provide another avenue for quantum technologies to continue to develop.
Low Temperature Physics, Volume 48, Issue 5, Page 396399, May 2022. <br/>By considering an arbitrary twoqubit state, it is shown that the Fisher information is intrinsically linked to the geometric discord which allows a measure for quantum correlations beyond entanglement. The complex amplitude of oscillations of the probability density function is upper bounded by the geometric discord which subsequently results in the Fisher information being bounded by the geometric discord. This gives an experimental observable which can be used to quantify quantum correlations beyond entanglement. This observable can be used to witness quantum correlations in an interferometry experiment, and provide another avenue for quantum technologies to continue to develop.
The link between Fisher information and geometric discord
10.1063/10.0010204
Low Temperature Physics
20220511T03:45:10Z
© 2022 Author(s).
A. Lowe
I. V. Yurkevich

Quantum rotator and Josephson junction: Compact vs. extended phase and dissipative quantum phase transition
https://aip.scitation.org/doi/10.1063/10.0010205?af=R&feed=mostrecent
Low Temperature Physics, <a href="https://aip.scitation.org/toc/ltp/48/5">Volume 48, Issue 5</a>, Page 400412, May 2022. <br/>This paper reassesses the old dilemma “compact vs. extended phase” in the quantum theory of the rotator and the Josephson junction and the analogy of these two systems with a particle moving in a periodic potential. This dilemma is in fact the dilemma of whether the states with the phases φ and φ + 2π are distinguishable, or not. In the past it was widely accepted that in the Josephson junction these states are distinguishable, as in the case of a particle moving in a periodic potential. This paper argues that the states with the phases φ and φ + 2π are indistinguishable as in a pendulum (a particular example of the quantum rotator). However, this does not lead to revision of the conclusions of the conventional theory predicting the transition from the superconducting to the insulating state in the small Josephson junction.
Low Temperature Physics, Volume 48, Issue 5, Page 400412, May 2022. <br/>This paper reassesses the old dilemma “compact vs. extended phase” in the quantum theory of the rotator and the Josephson junction and the analogy of these two systems with a particle moving in a periodic potential. This dilemma is in fact the dilemma of whether the states with the phases φ and φ + 2π are distinguishable, or not. In the past it was widely accepted that in the Josephson junction these states are distinguishable, as in the case of a particle moving in a periodic potential. This paper argues that the states with the phases φ and φ + 2π are indistinguishable as in a pendulum (a particular example of the quantum rotator). However, this does not lead to revision of the conclusions of the conventional theory predicting the transition from the superconducting to the insulating state in the small Josephson junction.
Quantum rotator and Josephson junction: Compact vs. extended phase and dissipative quantum phase transition
10.1063/10.0010205
Low Temperature Physics
20220511T03:45:10Z
© 2022 Author(s).
Edouard B. Sonin

Swirling selfgravitating vortex as the imagination of the Hoag’s ring galaxy
https://aip.scitation.org/doi/10.1063/10.0010206?af=R&feed=mostrecent
Low Temperature Physics, <a href="https://aip.scitation.org/toc/ltp/48/5">Volume 48, Issue 5</a>, Page 413419, May 2022. <br/>It is shown that based on the concept of a toroidal selfgravitating ring vortex with a swirl (with an orbital motion along the torus generatrix), it is possible to explain all the main morphological features of the famous Hoag ring galaxy, including the still unexplained rotation of the central elliptical galaxy. The astronomical observations can be used, thus, to study complex vortex motions [The article based on the authors’ reports Bannikova et al., XIII International Conference to 100 years of Illia Mikhailovich Lifshitz, Kharkiv, KhNU (2017) and Kontorovich et al., XIV International Science Conference “Physical phenomena in solids”, Kharkiv, KhNU (2019) at the Conferences on condensed matter physics at Kharkiv National University, the first of which was dedicated to the 100th anniversary of the birth of Ilya Mikhailovich Lifshitz, a teacher and friend of Mark Azbel.].
Low Temperature Physics, Volume 48, Issue 5, Page 413419, May 2022. <br/>It is shown that based on the concept of a toroidal selfgravitating ring vortex with a swirl (with an orbital motion along the torus generatrix), it is possible to explain all the main morphological features of the famous Hoag ring galaxy, including the still unexplained rotation of the central elliptical galaxy. The astronomical observations can be used, thus, to study complex vortex motions [The article based on the authors’ reports Bannikova et al., XIII International Conference to 100 years of Illia Mikhailovich Lifshitz, Kharkiv, KhNU (2017) and Kontorovich et al., XIV International Science Conference “Physical phenomena in solids”, Kharkiv, KhNU (2019) at the Conferences on condensed matter physics at Kharkiv National University, the first of which was dedicated to the 100th anniversary of the birth of Ilya Mikhailovich Lifshitz, a teacher and friend of Mark Azbel.].
Swirling selfgravitating vortex as the imagination of the Hoag’s ring galaxy
10.1063/10.0010206
Low Temperature Physics
20220511T03:45:09Z
© 2022 Author(s).
V. M. Kontorovich
S. A. Poslavskyi

Edge reconstruction and emergent neutral modes in integer and fractional quantum Hall phases
https://aip.scitation.org/doi/10.1063/10.0010207?af=R&feed=mostrecent
Low Temperature Physics, <a href="https://aip.scitation.org/toc/ltp/48/5">Volume 48, Issue 5</a>, Page 420427, May 2022. <br/>This paper comprises a review of our recent works on fractional chiral modes that emerge due to edge reconstruction in integer and fractional quantum Hall (QH) phases. The new part added is an analysis of edge reconstruction of the ν = 2/5 phase. QH states are topological phases of matter featuring chiral gapless modes at the edge. These edge modes may propagate downstream or upstream and may support either charge or chargeneutral excitations. From topological considerations, particlelike QH states are expected to support only downstream charge modes. However the interplay between the electronic repulsion and the boundary confining potential may drive certain quantum phase transitions (called reconstructions) at the edge, which are associated to the nucleation of additional pairs of counterpropagating modes. Employing variational methods, here we study edge reconstruction in the prototypical particlelike phases at ν = 1, 1/3, and 2/5 as a function of the slope of the confining potential. Our analysis shows that subsequent renormalization of the edge modes, driven by disorderinduced tunnelling and intermode interactions, may lead to the emergence of upstream neutral modes. These predictions may be tested in suitably designed transport experiments. Our results are also consistent with previous observations of upstream neutral modes in these QH phases and could explain the absence of anyonic interference in electronic MachZehnder setups.
Low Temperature Physics, Volume 48, Issue 5, Page 420427, May 2022. <br/>This paper comprises a review of our recent works on fractional chiral modes that emerge due to edge reconstruction in integer and fractional quantum Hall (QH) phases. The new part added is an analysis of edge reconstruction of the ν = 2/5 phase. QH states are topological phases of matter featuring chiral gapless modes at the edge. These edge modes may propagate downstream or upstream and may support either charge or chargeneutral excitations. From topological considerations, particlelike QH states are expected to support only downstream charge modes. However the interplay between the electronic repulsion and the boundary confining potential may drive certain quantum phase transitions (called reconstructions) at the edge, which are associated to the nucleation of additional pairs of counterpropagating modes. Employing variational methods, here we study edge reconstruction in the prototypical particlelike phases at ν = 1, 1/3, and 2/5 as a function of the slope of the confining potential. Our analysis shows that subsequent renormalization of the edge modes, driven by disorderinduced tunnelling and intermode interactions, may lead to the emergence of upstream neutral modes. These predictions may be tested in suitably designed transport experiments. Our results are also consistent with previous observations of upstream neutral modes in these QH phases and could explain the absence of anyonic interference in electronic MachZehnder setups.
Edge reconstruction and emergent neutral modes in integer and fractional quantum Hall phases
10.1063/10.0010207
Low Temperature Physics
20220511T03:45:07Z
© 2022 Author(s).
Udit Khanna
Moshe Goldstein
Yuval Gefen