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Quantum Computing with Spin Qubits Interacting Through Delocalized Excitons: Overcoming Hole Mixing

Brendon W. Lovett·Ahsan Nazir·Ehoud Pazy·Sean D. Barrett·Tim P. Spiller·G. Andrew D. Briggs
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Abstract

As a candidate scheme for controllably coupled qubits, we consider two quantum dots, each doped with a single electron. The spin of the electron defines our qubit basis and trion states can be created by using polarized light; we show that the form of the excited trion depends on the state of the qubit. By using the Luttinger-Kohn Hamiltonian we calculate the form of these trion states in the presence of light-heavy hole mixing, and show that they can interact through both the Förster transfer and static dipole-dipole interactions. Finally, we demonstrate that by using chirped laser pulses, it is possible to perform a two-qubit gate in this system by adiabatically following the eigenstates as a function of laser detuning. These gates are robust in that they operate with any realistic degree of hole mixing, and for either type of trion-trion coupling.

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Brendon W. Lovett, Ahsan Nazir, Ehoud Pazy, Sean D. Barrett, Tim P. Spiller, G. Andrew D. Briggs. 2005-10-04. Quantum Computing with Spin Qubits Interacting Through Delocalized Excitons: Overcoming Hole Mixing. https://doi.org/10.1103/physrevb.72.115324

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