Multi-spin errors in the optical control of a spin quantum memory
arXiv:0805.2407 · doi:10.1103/PhysRevB.78.165324
Abstract
We study a quantum memory composed of an array of charged quantum dots embedded in a planar cavity. Optically excited polaritons, i.e. exciton-cavity mixed states, interact with the electron spins in the dots. Linearly polarized excitation induces two-spin and multi-spin interactions. We discuss how the multi-spin interaction terms, which represent a source of errors for two-qubit quantum gates, can be suppressed using local control of the exciton energy. We show that using detuning conditional phase shift gates with high fidelity can be obtained. The cavity provides long-range spin coupling and the resulting gate operation time is shorter than the spin decoherence time.
4 pages, 4 figures
References in corpus (20)
- Elementary gates for quantum computation
- The Physical Implementation of Quantum Computation
- Coupling Superconducting Qubits via a Cavity Bus
- Complete Characterization of a Quantum Process: the Two-Bit Quantum Gate
- Coherent Population Trapping of Single Spins in Diamond Under Optical Excitation
- Stimulated and spontaneous optical generation of electron spin coherence in charged GaAs quantum dots
- Observation of Faraday rotation from a single confined spin
- Fast initialization of the spin state of an electron in a quantum dot in the Voigt configuration
- Theory of Fast Quantum Control of Exciton Dynamics in Semiconductor Quantum Dots
- Long-range spin-qubit interaction mediated by microcavity polaritons
- Three and Four-Body Interactions in Spin-Based Quantum Computers
- Millisecond spin-flip times of donor-bound electrons in GaAs
- Light-mass Bragg cavity polaritons in planar quantum dot lattices
- Coherent optical control of spin-spin interaction in doped semiconductors
- Ultralong-range radiative excitation transfer between quantum dots in a planar microcavity
- Microcavity polaritons in disordered exciton lattices
- Single-photon exchange interaction in a semiconductor microcavity
- Spin entanglement using coherent light and cavity-QED
- Entanglement and errors in the control of spins by optical coupling
- Switching the sign of photon induced exchange interactions in semiconductor microcavities with finite quality factors