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Entanglement production in a chaotic quantum dot

C. W. J. Beenakker·M. Kindermann·C. M. Marcus·A. Yacoby
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Abstract

It has recently been shown theoretically that elastic scattering in the Fermi sea produces quantum mechanically entangled states. The mechanism is similar to entanglement by a beam splitter in optics, but a key distinction is that the electronic mechanism works even if the source is in local thermal equilibrium. An experimental realization was proposed using tunneling between two edge channels in a strong magnetic field. Here we investigate a low-magnetic field alternative, using multiple scattering in a quantum dot. Two pairs of single-channel point contacts define a pair of qubits. If the scattering is chaotic, a universal statistical description of the entanglement production (quantified by the concurrence) is possible. The mean concurrence turns out to be almost independent on whether time-reversal symmetry is broken or not. We show how the concurrence can be extracted from a Bell inequality using low-frequency noise measurements, without requiring the tunneling assumption of earlier work.

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C. W. J. Beenakker, M. Kindermann, C. M. Marcus, A. Yacoby. 2003-10-09. Entanglement production in a chaotic quantum dot. https://doi.org/10.1007/1-4020-2193-3_10

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