Berlin 2012 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 12: Transport: Nanoelectronics I - Quantum Dots, Wires, Point Contacts 2

TT 12.3: Talk

Monday, March 26, 2012, 15:30–15:45, BH 334

Dynamic production of entanglement in spin blockade quantum dots — •Rafael Sánchez and Gloria Platero — Instituto de Ciencia de Materiales de Madrid (ICMM-CSIC)

Double quantum dots connected in series to source and drain electronic reservoirs can be tuned to show current suppression due to Pauli exclusion principle [1]. This effect is known as spin blockade. Driving the system with time dependent magnetic fields allows the coherent manipulation of the two electron states. Single spin rotations removes Pauli correlations and restitutes the flow of current [2,3]. Analyzing the current spectrum as a function of the driving frequency, we find dark resonances where spin blockade is restored due to collective rotations of the two spins. Furthermore, for such frequencies the system evolves towards a maximally entangled stationary state [4]. There, Rabi oscillations of two positive parity Bell states are robust for weak coupling to the reservoirs at low enough temperatures. We investigate the influence of the magnetic field polarization.
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F.H.L. Koppens, C. Buizert, K. J. Tielrooij, I. T. Vink, K. C. Nowack, T. Meunier, L. P. Kouwenhoven, L. M. K. Vandersypen, Nature 442, 766 (2006).
R. Sánchez, C. López-Monís, G. Platero, Phys. Rev. B 77, 165312 (2008).
R. Sánchez, G. Platero, in preparation