Quantum Information Processing Using Quantum Dot Spins and Cavity QED

TLDR

Electronic spin degrees of freedom in semiconductors have decoherence times several orders of magnitude longer than other relevant time scales. The study proposes a scheme for controlled interactions between two distant quantum dot spins to enable a solid‑state quantum computer based on localized electron spins as qubits. The scheme uses a high‑finesse microcavity vacuum field and conduction‑band‑hole Raman transitions driven by classical lasers to mediate long‑range interactions, enabling parallel CNOT operations and arbitrary single‑qubit rotations.

Abstract

The electronic spin degrees of freedom in semiconductors typically have decoherence times that are several orders of magnitude longer than other relevant time scales. A solid-state quantum computer based on localized electron spins as qubits is therefore of potential interest. Here, a scheme that realizes controlled interactions between two distant quantum dot spins is proposed. The effective long-range interaction is mediated by the vacuum field of a high finesse microcavity. By using conduction-band-hole Raman transitions induced by classical laser fields and the cavity-mode, parallel controlled-not operations, and arbitrary single qubit rotations can be realized.