Dynamical Quantum Phase Transition and Thermal Equilibrium in the Lattice Thirring Model

Mari Carmen Bañuls^1,2, Krzysztof Cichy³, Hao-Ti Hung^4,5*, Ying-Jer Kao^4,5,6, C.-J. David Lin^7,8, Amit Singh^9,10

¹Max-Planck Institut für Quantenoptik, Garching, Germany
²Munich Centre for Quantum Science and Technology (MCQST), Munich, Germany
³Faculty of Physics, Adam Mickiewicz University, Poznań, Poland
⁴Department of Physics, National Taiwan University, Taipei, Taiwan
⁵Center for Theoretical Physics, National Taiwan University, Taipei, Taiwan
⁶Center for Quantum Science and Technology, National Taiwan University, Taipei, Taiwan
⁷Institute of Physics, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
⁸Centre for High-energy Physics, Chung-Yuan Christian University, Chung-Li, Taiwan
⁹Department of Mechanical Engineering, National Yang Ming Chiao Tung University, Hsinchu, Taiwan
¹⁰Department of Physics and Astronomy, University of Manchester, Manchester, UK

* Presenter:Hao-Ti Hung, email:HungHaoTi852@gmail.com

In this presentation, we will discuss our study on dynamical quantum phase transitions (DQPTs) and the Loschmidt echo, which can be interpreted as a dynamical free energy. We discretize the Thirring model onto a 1D infinite-size lattice, mapping it to an XXZ model with a staggered magnetic field. Using the time-dependent variational principle (TDVP) and tensor network algorithms, we perform quantum quenches to investigate DQPTs in the Thirring model. Our findings reveal a critical energy threshold, beyond which DQPTs occur. Additionally, we simulate the effective inverse temperature, β, of the initial states and plot the DQPTs on the β-t plane, with the relationship between this plot and Fisher zeros requiring further investigation.

Keywords: Thirring model, DQPT, TDVP