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DTSTAMP:20201129T135349Z
LAST-MODIFIED:20201123T194857Z
DTSTART:20201202T180000Z
DTEND:20201202T190000Z
UID:event2370@bu.edu
URL:http://physics.bu.edu/events/show/2370
SUMMARY:Geometric properties of adiabatic thermal machines
DESCRIPTION:Featuring Liliana Arrachea\, Departamento de Fisica\, Facultad
de Ciencias Exactas y Naturales Universidad de Buenos Aires \n\nPart of the
Biophysics/Condensed Matter Seminar Series.\n\nStarting from the seminal w
orks of Aharonov and Bohm and Berry\, geometric effects have pervaded many
areas of physics. In quantum transport\, distinct contributions of geometri
c origin affect charge and energy currents. In the absence of an additional
dc bias\, the pumped charge in a periodically driven system was shown to b
e of geometric origin\, and can thus be expressed in terms of a closed-path
integral in parameter space\, akin to the Berry phase. Geometric concepts
like a thermodynamic metric and a thermodynamic length were recently intro
duced as promising tools to characterize the dissipated energy and to desig
n optimal driving protocols. Similar ideas are behind the description of th
e adiabatic time-evolution of many-body ground states of closed systems in
terms of a geometric tensor. \nThis large body of work linking geometry to
transport naturally hints at similar connections for thermal machines. In t
his seminar\, I will discuss how\, under quite general assumptions\, the op
eration of quantum thermal machines and the underlying heat-work conversion
is fundamentally tied to such geometric effects. We recently formulated a
unified description in terms of a geometric tensor for all the relevant ene
rgy fluxes\, which we refer to as thermal geometric tensor [1]. Within this
description\, pumping and dissipation are\, respectively\, associated with
the antisymmetric and symmetric components of this tensor. Simple examples
of the operation are a slowly driven qubit asymmetrically coupled to two b
osonic reservoirs kept at different temperatures\, and a quantum dot driven
by a rotating magnetic field and strongly coupled to electron reservoirs w
ith different polarizations.\n[1]Geometric properties of adiabatic quantum
thermal machines (https://journals.aps.org/prb/abstract/10.1103/PhysRevB.10
2.155407\, arXiv:2002.02225)\nBibek Bhandari\, Pablo TerrĂ©n Alonso\, Fabio
Taddei\, Felix von Oppen\, Rosario Fazio\, Liliana Arrachea
LOCATION: \, \,
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