Tapio Ala-Nissilä

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Stochastic thermodynamics offers a powerful formalism to study
fluctuating thermodynamic variables, such as (free) energy, entropy,
heat, and work in small systems driven beyond the linear response
regime. Small electronic devices, such as single-electron boxes and
quantum dots have been recently shown to provide well-controlled
benchmarks for stochastic thermodynamics. In particular, it is
possible to realize the ubiquitous concepts of a Szilard engine and
a Maxwell’s demon in such systems. While stochastic
thermodynamics gives a complete theoretical picture for devices such
as the Maxwell’s demon at classical level, attempts to generalize the
concept of work (and other thermodynamic quantities) to open
quantum systems have met with some difficulties. The main problem
in quantum mechanics is that there is no unique work operator, since
for irreversible processes work depends both on the state of the
system as well as the path taken.

In this talk I will discuss the analysis of devices such as the
Maxwell’s demon based on stochastic thermodynamics at the classical
level. I will then describe some recent progress in defining work
and its moments for quantum systems within the two-measurement
protocol (TMP) approach, which for isolated systems coincides with the
classical definition of work in the appropriate limit. In particular, I will
show that using the TMP within the Linblad master equation formalism
yields explicit results for driven, open quantum systems.

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Aalto University, Helsinki
TP seminar room 0.03
Contact: Joachim Krug