Physical Review B

Statistics of orbital entanglement production in a chaotic quantum dot with nonideal contacts

Francisco A. G. Almeida, André M. C. Souza

Published Sep 13, 2010• 13 citations

Abstract

We investigate the statistics of orbital entanglement production between electrons in a chaotic quantum dot with two-channel leads. Through a random-matrix simulation, we obtain the probability density of two entanglement measures, concurrence and entanglement formation, by varying the transparency of the contacts in the presence and absence of time-reversal invariance of the electron dynamics inside the cavity. The results suggest that orbital entanglement production is optimized by increasing the asymmetry between the transparency of the contacts, especially when time-reversal invariance is broken.

DOI: 10.1103/physrevb.82.115422

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Physical Review B

Statistics of orbital entanglement production in a chaotic quantum dot with nonideal contacts

Francisco A. G. Almeida, André M. C. Souza

Published Sep 13, 2010• 13 citations

Publisher

Abstract

DOI: 10.1103/physrevb.82.115422

Related papers

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We compute analytically the distributions of concurrence

\bm{\mathcal{C}}

and squared norm

\bm{\mathcal{N}}

for the production of electronic entanglement in a chaotic quantum dot. The dot is connected to the external world via one ideal and one partially transparent lead, characterized by the opacity

\gamma

. The average concurrence increases with

\gamma

while the average squared norm of the entangled state decreases, making it less likely to be detected. When a minimal detectable norm

\bm{\mathcal{N}}_0

is required, the average concurrence is maximal for an optimal value of the opacity

\gamma^\star(\bm{\mathcal{N}}_0)

which is explicitly computed as a function of

\bm{\mathcal{N}}_0

. If

\bm{\mathcal{N}}_0

is larger than the critical value

\bm{\mathcal{N}}_0^\star\simeq 0.3693\dots

, the average entanglement production is maximal for the completely ideal case, a direct consequence of an interesting bifurcation effect.

We compute analytically the distributions of concurrence

\text{C}

and squared norm

\text{N}

for the production of electronic entanglement in a chaotic quantum dot. The dot is connected to the external world via one ideal and one partially transparent lead, characterized by the opacity $\ensuremath{\gamma}$. The average concurrence increases with $\ensuremath{\gamma}$ while the average squared norm of the entangled state decreases, making it less likely to be detected. When a minimal detectable norm

{\text{N}}_{0}

is required, the average concurrence is maximal for an optimal value of the opacity ${\ensuremath{\gamma}}^{\ensuremath{\star}}({\text{N}}_{0})$ which is explicitly computed as a function of

{\text{N}}_{0}

. If

{\text{N}}_{0}

is larger than the critical value ${\text{N}}_{0}^{\ensuremath{\star}}\ensuremath{\simeq}0.3693\ensuremath{\cdots}$, the average entanglement production is maximal for the completely ideal case, a direct consequence of an interesting bifurcation effect.