2,142 research outputs found
Entropy production in a photovoltaic cell
We evaluate entropy production in a photovoltaic cell that is modeled by four
electronic levels resonantly coupled to thermally populated field modes at
different temperatures. We use a formalism recently proposed, the so-called
multiple parallel worlds, to consistently address the nonlinearity of entropy
in terms of density matrix. Our result shows that entropy production is the
difference between two flows: a semiclassical flow that linearly depends on
occupational probabilities, and another flow that depends nonlinearly on
quantum coherence and has no semiclassical analog. We show that entropy
production in the cells depends on environmentally induced decoherence time and
energy detuning. We characterize regimes where reversal flow of information
takes place from a cold to hot bath. Interestingly, we identify a lower bound
on entropy production, which sets limitations on the statistics of dissipated
heat in the cells.Comment: 7 pages, 2 figure
Exact correspondence between Renyi entropy flows and physical flows
We present a universal relation between the flow of a Renyi entropy and the
full counting statistics of energy transfers. We prove the exact relation for a
flow to a system in thermal equilibrium that is weakly coupled to an arbitrary
time-dependent and non-equilibrium system. The exact correspondence, given by
this relation, provides a simple protocol to quantify the flows of Shannon and
Renyi entropies from the measurements of energy transfer statistics.Comment: 9 pages, 5 figure
More on Reverse Triangle Inequality in Inner Product Spaces
Refining some results of S. S. Dragomir, several new reverses of the
generalized triangle inequality in inner product spaces are given. Among
several results, we establish some reverses for the Schwarz inequality. In
particular, it is proved that if is a unit vector in a real or complex
inner product space , and ,
then Comment: 12 page
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