Off-resonant two-photon-assisted electron transfer between quantum dots

Nutation oscillations of an electromagnetic wave propagating through an ensemble of quantum dots

“…In non-resonant electromagnetic field between these states an electromagnetically induced electron transfer takes place according to the derived conclusions [13]. There are no other levels which would be in resonance in electromagnetic field (4) with the states…”

“…Therefore, adjacent quantum dots with approximately equal energy levels in an electromagnetic field form peculiar nanoclusters, and an electromagnetic field provides an electron transfer between quantum dots which comprise one nanocluster. As this takes place, a nonresonance character of electromagnetic field allows to implement an electron transfer in a wide frequency range [13] which considerably expands the realm of nanoclusters in an electromagnetic field. Note, that there lacks a typical tunnelling between levels of various quantum dots, between which an electron transfer occurs.…”

“…Thus, an electron transfer between levels of identical quantum dots at one-photon resonance was considered in [1][2][3][4][5][6][7][8], and [9][10][11][12] treated transfer processes at a combinational and two-photon resonance between discrete levels of an electron system of two quantum dots with essentially different energies. In [13] the case is considered when the levels relating to two different but not necessary identical quantum dots possess approximately similar energy, and it was shown that the system is enough to be affected by electromagnetic field with only one carrier frequency for an electron transfer between quantum dots, and it is not obligatory for any resonance condition to be obeyed. Therefore, adjacent quantum dots with approximately equal energy levels in an electromagnetic field form peculiar nanoclusters, and an electromagnetic field provides an electron transfer between quantum dots which comprise one nanocluster.…”

Fast long-distance control of spin qubits by photon-assisted cotunneling

“…We get the natural result that the cotunneling is ultimately limited by the states lifetime /γ . The inverse distance decay, 1/d for d > d 0 , originates from destructive interferences of the phases φ q , a general feature [64][65][66]. Such interferences do not influence the incoherent leakage, which will therefore ultimately dominate at large distances.…”

“…While terms contributing to the leakage (incoherent process) are all positive, there are nontrivial phases appearing in the cotunneling, which is a coherent process. The phases depend on the particle correlations in the band and their destructive interference is very general [65]. Devising ways to suppress such interference is probably the most important factor in inducing effective long-range cotunneling.…”