AAPPS bulletin

October 2023Vol 33

Research and Review
  • The theory of generalised hydrodynamics for the one-dimensional Bose gas

    Matthew L. Kerr & Karen V. Kheruntsyan

    Abstract This article reviews the recent developments in the theory of generalised hydrodynamics (GHD) with emphasis on the repulsive one-dimensional Bose gas. We discuss the implications of GHD on the mechanisms of thermalisation in integrable quantum many-body systems as well as its ability to describe far-from-equilibrium behaviour of integrable and near-integrable systems in a variety of quantum quench scenarios. We outline the experimental tests of GHD in cold-atom gases and its benchmarks

    More to Read
  • Extended topological mode in a one-dimensional non-Hermitian acoustic crystal

    Xulong Wang, Wei Wang & Guancong Ma

    Abstract In Hermitian topological systems, topological modes (TMs) are bound to interfaces or defects of a lattice. Recent discoveries show that non-Hermitian effects can reshape the wavefunctions of the TMs and even turn them into extended modes occupying the entire bulk lattice. In this letter, we experimentally demonstrate such an extended TM (ETM) in a one-dimensional (1D) non-Hermitian acoustic topological crystal. The acoustic crystal is formed by a series of coupled acoustic resonant cav

    More to Read
  • Enhanced parameter estimation by measurement of non-Hermitian operators

    Jianning Li, Haodi Liu, Zhihai Wang & X. X. Yi

    Abstract Quantum metrology aims at delivering new quantum-mechanical improvement to technologies of parameter estimations with precision bounded by the quantum Cramér-Rao bound. The currently used quantum Cramér-Rao bound was established with measurements of observables restricted to be Hermitian. This constrains the bound and limits the precision of parameter estimation. In this paper, we lift the constraint and derive a previously unknown quantum Cramér-Rao bound. We find that the new bound c

    More to Read
  • An overview of polarized neutron instruments and techniques in Asia Pacific

    Chenyang Jiang

    Abstract Polarized neutron scattering is an indispensable tool for exploring a vast range of scientific phenomena. With its dynamic scientific community and significant governmental support as well as the rapid economic growth, the Asia–Pacific region has become a key player in the worldwide neutron scattering arena. From traditional research reactors to cutting-edge spallation neutron sources, this region is home to a myriad of advanced instruments offering a wide range of polarized neutron ca

    More to Read
  • Functional determinant approach investigations of heavy impurity physics

    Jia Wang

    Abstract In this brief review, we report some new development in the functional determinant approach (FDA), an exact numerical method, in the studies of a heavy quantum impurity immersed in Fermi gases and manipulated with radio-frequency pulses. FDA has been successfully applied to investigate the universal dynamical responses of a heavy impurity in an ultracold ideal Fermi gas in both the time and frequency domain, which allows the exploration of the renowned Anderson’s orthogonality catastro

    More to Read
  • Fokker-Planck equations for a trapped particle in a quantum-thermal Ohmic bath: general theory and applications to Josephson junctions

    Koichiro Furutani & Luca Salasnich

    Abstract We consider a particle trapped by a generic external potential and under the influence of a quantum-thermal Ohmic bath. Starting from the Langevin equation, we derive the corresponding Schwinger-Keldysh action. Then, within the path-integral formalism, we obtain both the semiclassical Fokker-Planck equation and the quantum Fokker-Planck equation for this out-of-equilibrium system. In the case of an external harmonic potential and in the underdamped regime, we find that our Fokker-Planc

    More to Read
News and Views
  • ICWIP2023 AAPPS Report

    Srubabati Goswami and Vandana Nanal

    2 ICWIP2023 AAPPS Report by Srubabati Goswami and Vandana Nanal The 8th IUPAP International Conference on Women in Physics (ICWIP2023), organized by the Gender in Physics Working Group (GIPWG) of the Indian Physics Association (IPA) and Tata Institute of Fundamental Research (TIFR), was held online from July 10 to 14, 2023. ICWIP2023, hosted by the Homi Bhabha Centre for Science Education (HBCSE) of TIFR, was inaugurated by Prof. A. K. Sood, the principal scientific adviser to the Government of

    More to Read
  • The Physical Society of Japan (JPS): The 2023 AAPPS-JPS Award


    1 The Physical Society of Japan (JPS): The 2023 AAPPS-JPS Award by JPS In order to promote research in physics in our region, the Physical Society of Japan (JPS) and the Association of Asia Pacific Physical Societies (AAPPS) shall jointly award the “AAPPS-JPS Award” to young JPS members who achieve outstanding research results. The citations of the 2023 winners of the first AAPPS-JPS Award are listed below. Associate Professor Hiroaki Ishizuka Department of Physics, Tokyo Institute of Technolog

    More to Read