1206.3112 (Rui Li)

Controllable coupling between two singlet-triplet qubits    [PDF]

Rui Li

The exchange coupling of electron spins in a linear coupled 4 quantum dots system is used to produce the controllable coupling between two singlet-triplet qubits. We start from the original second quantized Hamiltonian of the 4 quantum dots system, an effective spin-spin interactions between electrons are obtained using a projecting operator method, then under a strong external magnetic field, the controllable XX coupling between two singlet-triplet qubits is extracted with a series of explicit parameters. The applications of this controllable coupling, e.g., swap operation and entanglement generation, are also discussed.

View original: http://arxiv.org/abs/1206.3112