1,676 research outputs found
Mesoscopic Physics and the Fundamentals of Quantum Mechanics
We start by reviewing some interesting results in mesoscopic physics
illustrating nontrivial insights on Quantum Mechanics. We then review the
general principles of dephasing (sometimes called "decoherence") of
Quantum-Mechanical interference by coupling to the environment degrees of
freedom. A particular recent example of dephasing by a current-carrying
(nonequilibrium) system is then discussed in some detail. This system is itself
a manifestly Quantum Mechanical one and this is another illustration of
detection without the need for "classical observers" etc. We conclude by
describing briefly a recent problem having to do with the orbital magnetic
response of conduction electrons (another manifestly Quantum Mechanical
property): The magnetic response of a normal layer (N) coating a
superconducting cylinder (S). Some recent very intriguing experimental results
on a giant paramagnetic component of this response are explained using special
states in the normal layer. It is hoped that these discussions illustrate not
only the vitality and interest of mesoscopic physics\cite{book} but also its
extreme relevance to fundamental issues in Quantum Mechanics.Comment: 25 pages 3 eps figure
Linear and Nonlinear Mesoscopic Thermoelectric Transport with Coupling to Heat Baths
Decades of research on thermoelectrics stimulated by the fact that nano- and
meso-scale thermoelectric transport could yield higher energy conversion
efficiency and output power has recently uncovered a new direction on inelastic
thermoelectric effects. We introduce the history, motivation, and perspectives
on mesoscopic inelastic thermoelectric effects.Comment: Invited by Comptes Rendu
Steps and dips in the ac conductance and noise of mesoscopic structures
The frequency dependence of the equilibrium ac conductance (or the noise
power spectrum) through a mesoscopic structure is shown to exhibit steps and
dips. The steps, at energies related to the resonances of the structure, are
closely related to the partial Friedel phases of these resonances, thus
allowing a direct measurement of these phases (without interferometry). The
dips in the spectrum are related to a destructive interference in the
absorption of energy by transitions between these resonances, in some
similarity with the Fano effect.Comment: 4 pages, 2 figure
Shot-noise in transport and beam experiments
Consider two Fermi gases with the same {\it average} currents: a transport
gas, as in solid-state experiments where the chemical potentials of terminal 1
is and of terminal 2 and 3 is , and a beam, i.e., electrons
entering only from terminal 1 having energies between and . By
expressing the current noise as a sum over single-particle transitions we show
that the temporal current fluctuations are very different: The beam is noisier
due to allowed single-particle transitions into empty states below .
Surprisingly, the correlations between terminals 2 and 3 are the same.Comment: 4 pages, 2 figure
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