Dresden 2011 – wissenschaftliches Programm

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TT: Fachverband Tiefe Temperaturen

TT 26: TR: Fluctuations and Noise

TT 26.1: Hauptvortrag

Dienstag, 15. März 2011, 14:00–14:30, HSZ 301

Quantum paradoxes in quantum transport — •Wolfgang Belzig¹ and Adam Bednorz^1,2 — ¹Fachbereich Physik, Universiät Konstanz, D-78457 Konstanz, Germany — ²Institute of Theoretical Physics, University of Warsaw, Hoza 69, PL-00681 Warsaw, Poland

The impossibility of measuring non-commuting quantum mechanical observables is one of the most fascinating consequences of the quantum mechanical postulates, relevant for correlation measurements of the electric current [1]. Hence, to date the investigation of quantum measurement and projection is a fundamentally interesting topic. We propose to test the concept of weak measurement of non-commuting observables in mesoscopic transport experiments, using a quasiprobablistic description [2]. As first example of a paradox, we derive an inequality for current correlators, which is satisfied by every classical probability but violated by high-frequency fourth-order cumulants in the quantum regime for experimentally feasible parameters [3]. Further paradoxes can be used to detect nonlocal quantum correlations (entanglement) in mesoscopic junctions far beyond the regime covered by the usual Bell inequalities.

[1] A. Bednorz and W. Belzig, Phys. Rev. Lett. 101, 206803 (2008).

[2] A. Bednorz and W. Belzig, Phys. Rev. B 81, 125112 (2010).

[3] A. Bednorz and W. Belzig, Phys. Rev. Lett. 105, 106803 (2010).