Applied Physics Research Articles

Field-Angle Dependence Reveals Odd-Parity Superconductivity in CeRh2As2

CeRh2As2 is an unconventional superconductor with multiple superconducting phases and Tc=0.26 K. When H∥c, it shows a field-induced transition at μ0H*=4 T from a low-field superconducting state SC1 to a high-field state SC2 with a large critical field of μ0Hc2=14 T. In contrast, for H⊥c, only the SC1 with μ0Hc2=2 T is observed. A simple model based on the crystal symmetry was able to reproduce the phase diagrams and their anisotropy, identifying SC1 and SC2 with even and odd parity superconducting states, respectively. However, additional orders were observed in the normal state which might have an influence on the change of the superconducting state at H*. Here, we present a comprehensive study of the angle dependence of the upper critical fields using magnetic ac susceptibility, specific heat, and torque on single crystals of CeRh2As2. The experiments show that the state SC2 is strongly suppressed when rotating the magnetic field away from the c axis and it disappears for an angle of 35°. This behavior agrees perfectly with our extended model of a pseudospin triplet state with d→ vector in the plane and hence allows us to conclude that SC2 is indeed the suggested odd-parity state.Received 11 January 2022Revised 13 April 2022Accepted 5 May 2022DOI:https://doi.org/10.1103/PhysRevX.12.031001Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI. Open access publication funded by the Max Planck Society.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasPhase diagramsQuantum phase transitionsSuperconductivityPhysical SystemsHeavy-fermion systemsLow-temperature superconductorsStrongly correlated systemsTechniquesAC susceptibility measurementsMagnetization measurementsSpecific heat measurementsCondensed Matter, Materials & Applied Physics

Resonant Inelastic X-Ray Scattering Study of Electron-Exciton Coupling in High- Tc Cuprates

Explaining the mechanism of superconductivity in the high-Tc cuprates requires an understanding of what causes electrons to form Cooper pairs. Pairing can be mediated by phonons, the screened Coulomb force, spin or charge fluctuations, excitons, or by a combination of these. An excitonic pairing mechanism has been postulated, but experimental evidence for coupling between conduction electrons and excitons in the cuprates is sporadic. Here we use resonant inelastic x-ray scattering to monitor the temperature dependence of the d_d exciton spectrum of Bi2Sr2CaCu2O8−x crystals with different charge carrier concentrations. We observe a significant change of the d_d exciton spectra when the materials pass from the normal state into the superconductor state. Our observations show that the d_d excitons start to shift up (down) in the overdoped (underdoped) sample when the material enters the superconducting phase. We attribute the superconductivity-induced effect and its sign reversal from underdoped to overdoped to the exchange coupling of the site of the d_d exciton to the surrounding copper spins.3 MoreReceived 7 January 2022Revised 24 May 2022Accepted 7 June 2022Corrected 30 December 2022DOI:https://doi.org/10.1103/PhysRevX.12.021068Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasExcitonsPairing mechanismsSuperconductivityTechniquesResonant inelastic x-ray scatteringCondensed Matter, Materials & Applied Physics

Comment on "Ultrahigh Convergent Thermal Conductivity of Carbon Nanotubes from Comprehensive Atomistic Modeling".

Received 14 September 2021Accepted 23 May 2022DOI:https://doi.org/10.1103/PhysRevLett.128.259601© 2022 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasPhononsThermal conductivityPhysical SystemsCarbon-based materialsNanotubesNanowiresTechniquesBoltzmann theoryMolecular dynamicsCondensed Matter, Materials & Applied Physics

Barbalinardo etal. Reply.

Received 28 January 2022Accepted 23 May 2022DOI:https://doi.org/10.1103/PhysRevLett.128.259602© 2022 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasPhononsThermal conductivityPhysical SystemsCarbon-based materialsNanotubesNanowiresTechniquesBoltzmann theoryMolecular dynamicsCondensed Matter, Materials & Applied Physics

Erratum: Unified description of cuprate superconductors using a four-band d−p model [Phys. Rev. Research 3 , 033157 (2021)

Received 3 June 2022DOI:https://doi.org/10.1103/PhysRevResearch.4.029002Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasPairing mechanismsSuperconductivityPhysical SystemsHigh-temperature superconductorsMott insulatorsStrongly correlated systemsTwo-dimensional electron systemTechniquesMonte Carlo methodsCondensed Matter, Materials & Applied Physics

Strong-Magnetic-Field Magnon Transport in Monolayer Graphene

At high magnetic fields, monolayer graphene hosts competing phases distinguished by their breaking of the approximate SU(4) isospin symmetry. Recent experiments have observed an even denominator fractional quantum Hall state thought to be associated with a transition in the underlying isospin order from a spin-singlet charge density wave at low magnetic fields to an antiferromagnet at high magnetic fields, implying that a similar transition must occur at charge neutrality. However, this transition does not generate contrast in typical electrical transport or thermodynamic measurements and no direct evidence for it has been reported, despite theoretical interest arising from its potentially unconventional nature. Here, we measure the transmission of ferromagnetic magnons through the two-dimensional bulk of clean monolayer graphene. Using spin polarized fractional quantum Hall states as a benchmark, we find that magnon transmission is controlled by the detailed properties of the low-momentum spin waves in the intervening Hall fluid, which is highly density dependent. Remarkably, as the system is driven into the antiferromagnetic regime, robust magnon transmission is restored across a wide range of filling factors consistent with Pauli blocking of fractional quantum Hall spin-wave excitations and their replacement by conventional ferromagnetic magnons confined to the minority graphene sublattice. Finally, using devices in which spin waves are launched directly into the insulating charge-neutral bulk, we directly detect the hidden phase transition between bulk insulating charge density wave and a canted antiferromagnetic phase at charge neutrality, completing the experimental map of broken-symmetry phases in monolayer graphene.3 MoreReceived 6 February 2021Revised 22 February 2022Accepted 28 April 2022DOI:https://doi.org/10.1103/PhysRevX.12.021060Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasFractional quantum Hall effectSpintronicsPhysical SystemsGrapheneCondensed Matter, Materials & Applied Physics

Scientometrics study of Indian journal of pure and applied physics

Thispaper presents Scientometrics study of The Indian Journal of Pure and Applied Physics during the period of 2010 to 2019. Researcher has to examined 853 articles been published during the period of study. The paper examined year wise distribution of articles, subjectwise distribution of articles, in Authorship pattern 2783 author was dected, The maximum number of contributions published 2012, 12th Issue, 50th Volume ; 149. The highest number of contributions published at single authors with 824; 39.60%, Two authors with 763; 27.41and the remaining 21 authors contributions with 657; 23.60%. The authorship pattern of the published in out of 2783 the maximum number of 824; (39.60%) had been contributed by single authors. 6. Out of 263 contributions are published in the journal of special issues. There are 117 contributions are published in the journal with 13.71%, and the remaining 35 contributions are published in the journal with 4.10%. Subject facet highest no of articles published i ,e. 251 papers have published in Electronic Structure, Magnetic and Optical properties. During the span of study have been analyzed.

Erratum: Nonlinear spectroscopy of excitonic states in transition metal dichalcogenides [Phys. Rev. B 105 , 115436 (2022)

Received 27 May 2022DOI:https://doi.org/10.1103/PhysRevB.105.239902©2022 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasExcitonsNonlinear optical susceptibilitySecond order nonlinear optical processesPhysical Systems2-dimensional systemsCondensed Matter, Materials & Applied Physics

Polarization-Dependent Selection Rules and Optical Spectrum Atlas of Twisted Bilayer Graphene Quantum Dots

Understanding how symmetries encode optical polarization information into selection rules in molecules and materials is important for their optoelectronic applications including spectroscopic analysis, display technology, and quantum computation. Here, we extend polarization-dependent selection rules from atoms to solid-state systems with various point groups with the help of the rotational operator for circular polarization and the twofold rotational operator (or reflection operator) for linear polarization. We use these new selection rules to study the optical properties of twisted bilayer graphene quantum dots (TBGQDs), which inherit advantages of graphene quantum dot including its ultrathin thickness, excellent biocompatibility, and shape- and size-tunable optical absorption or emission. We study how the electronic structures and optical properties of TBGQDs rely on size, shape, twist angle, and correlation effects for TBGQDs with 10 different point groups for which we obtain an optical selection rule database. We show how current operator matrix elements identify the generalized polarization-dependent selection rules. Our results show that both the electronic and optical band gaps follow power-law size scalings with a dominant role of the twist angle. We derive an atlas of optical conductivity spectra for both size and twist angle in TBGQDs. As a result of quantum confinement effects, in the atlas a new type of optical conductivity features emerges with multiple discrete absorption frequencies ranging from infrared to ultraviolet energy, allowing for applications in photovoltaic devices and photodetectors. The atlas and size scaling provide a full structure–symmetry-function interrelation and hence offer an excellent basis for the geometrical manipulation of optical properties of TBGQDs as building blocks for novel integrated carbon optoelectronics.2 MoreReceived 5 October 2021Revised 14 April 2022Accepted 3 May 2022DOI:https://doi.org/10.1103/PhysRevX.12.021055Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasElectronic structureOptical conductivityPhysical SystemsGrapheneTechniquesGroup theoryMean field theorySymmetriesTight-binding modelCondensed Matter, Materials & Applied Physics

Preface

Welcome to 2022 12th International Conference on Applied Physics and Mathematics (ICAPM 2022), which should be held in Singapore during February 18-20, 2022. Due to global travel restrictions because of the COVID-19 pandemic, the conference was organized as an online meeting. Despite this, despite the different time zones of participants, despite some unavoidable technical hazards the conference matched by far the expectation of researchers and specialists to be a place of discussions, a vitrine of the new achievements in the field of applied Physics and Mathematics.It has been successfully held in 11 consecutive years since 2011, respectively. In the past five years, ICAPM 2017, ICAPM 2018, ICAPM 2019, ICAPM 2020, and ICAPM 2021 Conference Proceedings have been archived into IOP Journal of Physics: Conference Series, indexed by ISI Web of Science (Conference Proceedings Citation Index (CPCI), Scopus, Engineering Information (EI), etc.List of Commitees are available in this pdf.

Preface

The 2022 International Conference on Applied Mathematics and Physics (ICAMP 2022) was held on April 15-17, 2022 as a virtual conference due to the growing concerns over the coronavirus outbreak (COVID-19), and in order to protect the well-being of our attendees, partners, and staff as our number one priority.The conference focused on the research areas of mathematics, applied mathematics and physics and aimed to provide a platform for experts and scholars from home and abroad who engaged in mathematics and physics research to share scientific research results and cutting-edge technologies, understand academic development trends, broaden research ideas, strengthen academic research and discussion, and promote cooperation in the industrialization of academic results. The conference will be held once a year as scheduled, inviting experts, scholars, entrepreneurs and other relevant personnel from universities and research institutions at home and abroad to attend the conference.This scientific event brings together more than 60 national and international researchers in applied mathematics and physics. During the conference, the conference model was divided into three sessions, including oral presentations, keynote speeches, and online Q&A discussion. In the first part, some scholars, whose submissions were selected as the excellent papers, were given about 5-10 minutes to perform their oral presentations one by one. Then in the second part, keynote speakers were each allocated 30-45 minutes to hold their speeches.List of Committee member, Conference Chairmen and Program Committees are available in this pdf.

The newly installed IBIL (Ion Beam Induced Luminescence) set-up at CEDAD-University of Salento: design and first applications on perovskite

We present the design and implementation of the new Ion Beam Induced Luminescence set-up recently installed and tested at the Centre of Applied Physics, Dating and Diagnostics of the University of Salento. The set-up allows the irradiation of samples at atmospheric pressure with MeV protons produced by a 3 MV Tandetron accelerator and extracted in air through a kapton membrane. Ion beam induced luminescence is collected by an optical fiber and analyzed by an imaging spectrometer. Simultaneously, characteristic X-Rays emitted by the sample are detected by a Silicon Drift Detector (SSD) detector. The system also allows combined photoluminescence measurements by using an excitation laser focused onto the samples. First applications in the analysis of all-inorganic perovskites (CsPbBr3) deposited by PLD (Pulsed Laser Deposition) are presented.

Numerical Investigation of Freeze Valve Melting Behavior in Molten Salt Reactor using OpenFOAM

Molten Salt Reactor (MSR) used a freeze valve to handle accident conditions when the reactor overheated and the active safety control systems failed. The freeze valve will melt if the reactor core temperature increases and exceeds the freeze valve’s melting temperature. In this research, a numerical investigation of freeze valve melting behavior was conducted. Freeze valve geometry used geometry proposed by Oak Ridge National Laboratory (ORNL) in Molten Salt Reactor Experiment (MSRE) and also used in test loop facility in Shanghai Institute of Applied Physics (SINAP) to develop Thorium Molten Salt Reactor (TMSR). The material used FLiNaK salt (LiF-NaF-KF, 46.5-11.5-42.0 mol %). Numerical calculation performs using OpenFOAM. BuoyantPimpleFoam was used to analyze the heat transfer mechanism. Isothermal phase-change simulated by adding solidificationMeltingSource terms into fvOptions as a flexible framework in OpenFOAM.

Preface

The 9th Asian Physics Symposium 2021 (APS 2021) held on 5-6 October 2021 virtually due to Covid-19 pandemic constraint is aimed in providing the forum of scientific communication and interaction among distinguished scientists working in the physics and its related fields. In this scientific event the latest research results were presented the state-of-the-art development in the field and help to guide our future research directions. It was also designed to offer the opportunity of making direct contacts for the young Indonesian scientists and students with well-known scientists abroad and thereby fostering the existing research collaborations and extending international research networking for the future.APS 2021 is organized by the Physics Department, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, in collaboration with HFI (Indonesian Physical Society), PAPSI (Physics and Applied Physics Society of Indonesia), HANI (Indonesian Nuclear Scientist Society), HRMI (Indonesian Material Research Society), HAGI (Indonesian Geophysicist Society) - West Java Chapter, and HFMBI (Indonesian Medical Physicist and Biophysicist Society).The program of APS 2021 featured 6 invited talks in 45 minutes for each plenary session and 192 contributed oral presentations in 10 minutes’ presentation and 5 minutes Q&A sessions, which come from 3 different countries: Japan, Turkey, and Indonesia. All abstracts have been reviewed and will be presented in this event.List of Advisory Boards, Technical Committee are available in this pdf.

Erratum: Pulay forces in density-functional theory with extended Hubbard functionals: From nonorthogonalized to orthogonalized manifolds [Phys. Rev. B 102 , 235159 (2020)

Received 14 May 2022DOI:https://doi.org/10.1103/PhysRevB.105.199901©2022 American Physical SocietyPhysics Subject Headings (PhySH)Research AreasFirst-principles calculationsTechniquesDensity functional theoryElectronic structureExtended Hubbard modelCondensed Matter, Materials & Applied Physics

Evidence for Realignment of the Charge Density Wave State in ErTe3 and TmTe3 under Uniaxial Stress via Elastocaloric and Elastoresistivity Measurements

We report the evolution of the charge density wave (CDW) states in the quasi-two-dimensional rare-earth tritellurides (RTe3 for R=Er, Tm) under the influence of in-plane uniaxial stress. Measurements of the elastocaloric effect, resistivity, and elastoresistivity allow us to demonstrate the importance of in-plane antisymmetric strain on the CDW and to establish a phase diagram. We show that modest tensile stress parallel to the in-plane a axis can reversibly switch the direction of the ordering wave vector between the two in-plane directions, and present a free-energy expansion which reproduces the general structure of the observed phenomena. This work opens a new avenue in the study of RTe3 in its own right, and more generally establishes RTe3 as a promising model system for the study of strain-CDW interactions in a quasi-two-dimensional square lattice.5 MoreReceived 7 January 2022Revised 13 March 2022Accepted 15 April 2022DOI:https://doi.org/10.1103/PhysRevX.12.021046Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasCharge density wavesStrainTechniquesCalorimetryResistivity measurementsCondensed Matter, Materials & Applied Physics

MICROWAVE ESTIMATION OF DIELECTRIC PROPERTIES OF BIOLOGICAL TISSUE UNDER THERMAL MODIFICATION

The aim of this study was to estimate changes of tissue dielectric parameters under the action of high temperature. We fixed the shifts of dielectric properties of biological tissue samples, associated with short-time influence of high temperature (600C, 5 min.) in vitro. The dielectric properties of tissues (permittivity - ε and conductivity - σ) were determined using original software and hardware complex for near-field resonant microwave sensing developed at the Institute of Applied Physics of the RAS. The study of these parameters was performed at a depth of 5 mm. It was found that short processing of a biological sample in moderate hyperthermia (600C) leads to significant change of dielectric characteristics of the tissue. This is manifested in a significant decrease in the dielectric permittivity (in 2.48 times for an intact specimen) and conductivity (on 25.3%) of the studied biological sample, due to its dehydration. It was shown that used regimen of heating decreases the permittivity and conductivity of tissue specimen that is associated with changes of its hydratation.

Fractional Spin Excitations in the Infinite-Layer Cuprate CaCuO2

We use resonant inelastic x-ray scattering (RIXS) to investigate the magnetic dynamics of the infinite-layer cuprate CaCuO2. We find that close to the (1/2,0) point, the single magnon decays into a broad continuum of excitations accounting for about 80% of the total magnetic spectral weight. Polarization-resolved RIXS spectra reveal the overwhelming dominance of the spin-flip (ΔS=1) character of this continuum with respect to the ΔS=0 multimagnon contributions. Moreover, its incident-energy dependence is identical to that of the magnon, supporting a common physical origin. We propose that the continuum originates from the decay of the magnon into spinon pairs, and we relate it to the exceptionally high ring exchange Jc∼J1 of CaCuO2. In the infinite-layer cuprates, long-range and multisite hopping integrals are very important, and they amplify the 2D quantum magnetism effects in spite of the 3D antiferromagnetic Néel order.Received 12 October 2021Accepted 30 March 2022DOI:https://doi.org/10.1103/PhysRevX.12.021041Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article’s title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasAntiferromagnetismExchange interactionMagnonsSpinonPhysical SystemsAntiferromagnetsCharge-transfer insulatorsHigh-temperature superconductorsTechniquesResonant inelastic x-ray scatteringCondensed Matter, Materials & Applied Physics

Simulation of Quantum Many-Body Dynamics with Tensor Processing Units: Floquet Prethermalization

Tensor processing units (TPUs) are specialized hardware accelerators developed by Google to support large-scale machine-learning tasks but they can also be leveraged to accelerate and scale other linear-algebra-intensive computations. In this paper, we demonstrate the usage of TPUs for massively parallel classical simulations of quantum many-body dynamics on long time scales. We apply our methods to study the phenomenon of Floquet prethermalization, i.e., exponentially slow heating in quantum spin chains subject to high-frequency periodic driving. We simulate the dynamics of L=34 qubits for over 105 Floquet periods, corresponding to circuits with 4×106 nearest-neighbor two-qubit gates. The circuits simulated have no additional symmetries and represent a pure-state evolution in the full 2L-dimensional Hilbert space. This is achieved by distributing the computation over 128 TPU cores. On that size TPU cluster, we find speed-ups in wall-clock run time of 230 times and 15 times when compared to reference CPU and single-graphics-processing-unit (GPU) simulations, respectively, for shorter-time 30-qubit simulations that can be handled by all three platforms. We study the computational cost of the simulations, as a function of both the number of qubits and the number of TPU cores used, up to our maximum capacity of L=40 qubits, which requires a “full pod” of 2048 TPU cores with tens of terabytes of memory in total. For these simulations, an eight-TPU-core machine is comparable to a single A100 GPU and thus the full TPU pod is comparable to a machine with hundreds of top-of-the-line GPUs. However, the TPU pod is more energy and cost efficient and readily accessible (via Google Cloud), unlike such large many-GPU configurations. We also study the accumulation of numerical error as a function of circuit depth in very deep circuits. Our work demonstrates that TPUs can offer significant advantages for state-of-the-art simulations of quantum many-body dynamics.Received 20 November 2021Accepted 20 April 2022DOI:https://doi.org/10.1103/PRXQuantum.3.020331Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasQuantum simulationPhysical SystemsFloquet systemsTechniquesNumerical techniquesQuantum InformationStatistical PhysicsCondensed Matter, Materials & Applied Physics

Symmetry-Protected Infinite-Temperature Quantum Memory from Subsystem Codes

We study a mechanism whereby quantum information present in the initial state of a quantum many-body system can be protected for arbitrary times due to a combination of symmetry and spatial locality. Remarkably, the mechanism is sufficiently generic that the dynamics can be fully ergodic upon resolving the protecting symmetry and fixing the encoded quantum state, resulting in a quantum memory that persists up to infinite temperature. After exemplifying the mechanism in a strongly nonintegrable two-dimensional (2D) spin model inspired by the surface code, we find it has a natural interpretation in the language of noiseless subsystems and stabilizer subsystem codes. This interpretation yields a number of further examples, including a nonintegrable Hamiltonian with quantum memory based on the Bacon-Shor code. The lifetime of the encoded quantum information in these models is infinite provided that the dynamics respect the stabilizer symmetry of the underlying subsystem code. In the presence of symmetry-violating perturbations, we make contact with previous work leveraging the concept of prethermalization to show that the encoded quantum information can acquire a parametrically long lifetime under dynamics with an enlarged continuous symmetry group. The prethermalization mechanism hinges on the application of external fields that are much larger than the perturbations themselves. We identify conditions on the underlying subsystem code that enable such a prethermal enhancement of the memory lifetime.3 MoreReceived 28 October 2021Revised 15 February 2022Accepted 1 April 2022DOI:https://doi.org/10.1103/PRXQuantum.3.020330Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.Published by the American Physical SocietyPhysics Subject Headings (PhySH)Research AreasQuantum memoriesQuantum InformationCondensed Matter, Materials & Applied Physics