Published in the Research School of Physics Event Horizon
Vol45 Issue45 9–13 November 2020
Research Highlights
In the recent paper <Physical Review Letters> 125, 190401 (2020), Xiwen Guan from TP, in collaboration with co-workers from Beijing Computational Science Research Center and Rice University, reported their study of fractional spin excitations, spin-charge separation, incoherent spin liquids, criticality and dynamical structure factors in one-dimensional (1D) Fermi gas. In this scenario, the observation of spin-charge separation is a long-standing challenge. Based on their analytical results of exact excitation spectra and low temperature behaviour of the model, they showed that the peaks of the charge and spin dynamical structure factors exhibit distinguishable propagating velocities of spin and charge as functions of interaction strength, which can be observed by Bragg spectroscopy with ultracold atoms. see https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.125.190401
In the paper <npj Quantum Information> 5:88 (2019), Xiwen Guan, in collaboration with co-workers from Zhejiang University, China and University of Massachusetts, reported their study on an interaction-driven many-particle quantum heat engine. They found universal interaction driven caloric effect in quantum systems and demonstrated the quantum heat engine based on the interaction driving of a many-particle working medium. The cycle alternates isochoric heating and cooling strokes with both interaction-driven processes that are simultaneously isochoric and isentropic. When the working substance is confined in a tight waveguide, the efficiency of the cycle becomes universal at low temperatures and governed by the ratio of velocities of a Luttinger liquid. See https://www.nature.com/articles/s41534-019-0204-5