102 research outputs found
Optically induced spin gates in coupled quantum dots using the electron-hole exchange interaction
We propose a fast optically induced two-qubit \textsc{c-phase} gate between
two resident spins in a pair of coupled quantum dots. An excited bound state
which extends over the two dots provides an effective electron-electron
exchange interaction. The gate is made possible by the electron-hole exchange
interaction, which isolates a single transition in the system. When combined
with appropriate single qubit rotations, this gate generates an entangled state
of the two spins
Optically Generated 2-Dimensional Photonic Cluster State from Coupled Quantum Dots
We propose a method to generate a two-dimensional cluster state of polarization encoded photonic qubits from two coupled quantum dot emitters. We combine the proposal for generating one-dimensional cluster state strings from a single dot, with a new proposal for an induced conditional phase gate between the two quantum dots. The entanglement between the two dots translates to entanglement between the two photonic cluster state strings. Further interpair coupling of the quantum dots using cavities and waveguides can lead to a two-dimensional cluster sheet, the importance of which stems from the fact that it is a universal resource for quantum computation. Analysis of errors indicates that our proposal is feasible with current technology. Crucially, the emitted photons need not have identical frequencies, and so there are no constraints on the resonance energies for the quantum dots
Deterministic generation of large-scale entangled photonic cluster state from interacting solid state emitters
The ability to create large highly entangled `cluster' states is crucial for
measurement-based quantum computing. We show that deterministic multi-photon
entanglement can be created from coupled solid state quantum emitters without
the need for any two-qubit gates and regardless of whether the emitters are
identical. In particular, we present a general method for controlled
entanglement creation by making direct use of the always-on exchange
interaction, in combination with single-qubit operations. This is used to
provide a recipe for the generation of two-dimensional, cluster-state entangled
photons that can be carried out with existing experimental capabilities in
quantum dots
- …