LABORATOIRE DE PHYSIQUE THEORIQUE DE LA MATIERE CONDENSEE

Prof Dr Irene D'Amico FInstP

Information Centre, Market Square
Department of Physics,                  
University of York,                   

"DFT-inspired Methods for Quantum Thermodynamics"

To understand how the increase of disorder in the macroscopic world follows from microscopic order we need to determine the so-called work distribution (which is related to the entropy production) for quantum systems performing suitable cyclic dynamics. This is a crucially difficult task, particularly so when interacting many-particle (or many-spin) systems are considered. Here [1] we study the quantum fluctuations of a many-body system by proposing a new method inspired by density functional theory (DFT). Through this method, we can estimate the transition matrix elements due to the system time-dependent dynamics and obtain an approximation to the work distribution and average work of the driven quantum many-body system. We apply this DFT-inspired approach to obtain the work distribution function of a driven Hubbard dimer using an approximation based on Kohn-Sham states. This model can represent different quantum system, including excitations in coupled quantum dots driven by laser pulses. We compare this new method with the exact result and show under which conditions this approximation is effective.

 

[1] "DFT-inspired Methods for Quantum Thermodynamics", M. Herrera, R. M. Serra, and I. D'Amico, submitted (2017) "arXiv:1703.02460"