Maria Carolina O. Aguiar, Thursday July 2 at 2:00 pm (Paris time), Room Charpak, at LPEM in hybrid format:Formation of charge and spin ordering in interacting one-dimensional systems during and after quantum quenches by Maria Carolina O. Aguiar
Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
In recent work by my group, we aim at investigating the emergence of charge and spin orderings within the extended Hubbard model during and after quantum quenches. We use the time-dependent density matrix renormalization group method to describe the dynamics.Starting from the non-interacting disordered state, we track its time evolution as electronic interactions increase over a finite time, eventually reaching final values in the charge density wave or spin density wave phase. These final values are considered for the free evolution of the system after the quench.
According to the rate at which we turn on the electronic interactions during the quench, we identify three temporal regimes: abrupt, intermediate, and adiabatic [1]. Systems subject to the adiabatic regime follow the instantaneous ground state during the quench and remain stable in the post-quench analysis, while those subject to abrupt changes do not present ordering during or after the quench. In between, in the intermediate case, after a significant increase during the quench, the order parameters exhibit oscillatory behavior in the post-quench, also observed in the entanglement entropy and the fidelity between states. Exact diagonalization analyses of small chains show that these oscillations arise from coherent superpositions within the low-energy spectrum of the Hamiltonian governing the post-quench dynamics.
[1] Isaac M. Carvalho et al., Phys. Rev. B 106, 195405 (2022).Zoom link: https://espci.zoom.us/j/89966538799?pwd=28YSL9zWaQ8ZvOcVbc9CabdBE4W7xu.1
ID: 899 6653 8799
Passcode: 284191
Departamento de Física, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
In recent work by my group, we aim at investigating the emergence of charge and spin orderings within the extended Hubbard model during and after quantum quenches. We use the time-dependent density matrix renormalization group method to describe the dynamics.Starting from the non-interacting disordered state, we track its time evolution as electronic interactions increase over a finite time, eventually reaching final values in the charge density wave or spin density wave phase. These final values are considered for the free evolution of the system after the quench.
According to the rate at which we turn on the electronic interactions during the quench, we identify three temporal regimes: abrupt, intermediate, and adiabatic [1]. Systems subject to the adiabatic regime follow the instantaneous ground state during the quench and remain stable in the post-quench analysis, while those subject to abrupt changes do not present ordering during or after the quench. In between, in the intermediate case, after a significant increase during the quench, the order parameters exhibit oscillatory behavior in the post-quench, also observed in the entanglement entropy and the fidelity between states. Exact diagonalization analyses of small chains show that these oscillations arise from coherent superpositions within the low-energy spectrum of the Hamiltonian governing the post-quench dynamics.
[1] Isaac M. Carvalho et al., Phys. Rev. B 106, 195405 (2022).Zoom link: https://espci.zoom.us/j/89966538799?pwd=28YSL9zWaQ8ZvOcVbc9CabdBE4W7xu.1
ID: 899 6653 8799
Passcode: 284191
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