Seminar with postdoctorate Massimo Ostilli – August 11, 2017 – 10h10min
THE PHYSICS GRADUATE PROGRAM invites everyone to the seminar:
Thermalization in black-body radiation and application to the Lipkin-Meshkov-Glick model.
Massimo Ostilli
Pós-doutorando/UFSC
Abstract:
In a recent work, we have derived simple Lindblad-based equations for the thermalization of systems in contact with a thermal reservoir. Here, we apply these equations to the Lipkin-Meshkov-Glick model (LMG) in contact with a blackbody radiation and analyze the dipole matrix elements involved in the thermalization process. We find that the thermalization can be complete only if the density is sufficiently high, while, in the limit of low density, the system thermalizes partially, namely, within the Hilbert subspaces where the total spin has a fixed value. In this regime, and in the isotropic case, we evaluate the characteristic thermalization time analytically, and show that it diverges with the system size in correspondence of the critical points and inside the ferromagnetic region. Quite interestingly, at zero temperature the thermalization time diverges only quadratically with the system size, whereas quantum adiabatic algorithms, aimed at finding the ground state of same system, imply a cubic divergence of the required adiabatic time.
Date: August 11, 2017 – (friday) – Place: Sala 212 – Auditório do Departamento de Física – Time: 10h10min
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