Electrical Spin Injection into Single InGaAs Quantum Dots

Pulsed Electrical Spin Injection into InGaAs Quantum Dots: Studies of the Electroluminescence Polarization Dynamics

“…A crucial factor may be the potential barrier at the n-ZnMnSe/i-GaAs interface, which the carriers have to pass by a (phonon-assisted) tunnelling process [3,4]. When the carrier density at the beginning of the pulse is still low, spin-polarized electrons can easily tunnel into the empty QD states and retain their polarization.…”

“…As has been shown, the band bending and the position of the electronic quasi-Fermi level give rise to a tunnel barrier and often the formation of a twodimensional electron gas (2DEG) at the III-V / II-VI interface. Further details may be found in [3,4] and references therein.…”

Dinámica de la polarización del espín electrónico y nuclear en trampas paramagnéticas de Ga en GaAsN

“…Esto se debe principalmente a la relajación del espín y la decoherencia cuántica. Ejemplo de esto son los métodos convencionales para detectar y generar corrientes de polarización de espín en sistemas como: diodos emisores de luz [4], puntos cuánticos [5,6], nanotubos de carbono [6], semiconductores ferromagnéticos [7] o semiconductores magnéticos diluidos [8].…”

“…GaAsN dilute semiconductors have attracted significant attention mainly due to their applications in telecommunications [1], photovoltaic devices with efficiency close to 50% [2], and optoelectronic devices in general [3]. The unusually large bowing parameter of semiconductor alloys containing N considerably diminishes their band gap [4,5] allowing to tune their emission wave length within the telecommunication range [6]. Even though the incorporation of a small amount of N in the crystal lattice of GaAs deteriorates the photoluminescence and carrier lifetime [7,8], it introduces new and interesting properties regarding the spin polarization of conduction band (CB) electrons [6].…”

“…Negatively charged nitrogen-vacancy centers in diamond [1][2][3][4][5], phosphorous atom impurities in silicon [6][7][8][9][10][11], and other schemes based on point defects embedded in semiconductors have been widely studied as alternatives to develop quantum bits [12,13]. One of the necessary conditions for quantum computing is long electron spin decoherence times to ensure a minimum of fault tolerance [10,14].…”