Double-occupancy probability and entanglement of two holes in double Ge/Si quantum dots
A. I. Yakimov, A. A. Bloshkin, A. V. Dvurechenskii
Rzhanov Institute of Semiconductor Physics, Siberian Branch RAS
630090 Novosibirsk, Russia
Abstract
We have calculated the exchange energy, double
occupation probability of the lowest singlet state, and degree of
entanglement of two holes in vertically coupled double Ge/Si
quantum dots. We determined the conditions on which the exchange
coupling is large enough for a fast swap operation in quantum
computation and the double-occupancy probability is still low,
thus maximizing the entanglement for a small computation error. We
found that both the degree of entanglement and double-occupancy
probability for quantum dots with different dot size collapse
onto universal, size independent curves when plotted as a function
of singlet-triplet splitting.