The implementation of quantum entangling gates between qubits is essential to achieve scalable quantum computation. Here, we propose a robust scheme to realize an entangling gate for distant solid-state spins via a mechanical oscillator in its thermal equilibrium state. By appropriate Hamiltonian engineering and usage of a protected subspace, we show that the proposed scheme is able to significantly reduce the thermal effect of the mechanical oscillator on the spins. In particular, we demonstrate that a high entangling gate fidelity can be achieved even for a relatively high thermal occupation. Our scheme can thus relax the requirement for ground-state cooling of the mechanical oscillator, and may find applications in scalable quantum information processing in hybrid solid-state architectures.

Reference: Puhao Cao, Ralf Betzholz, Shaoliang Zhang, and Jianming Cai, Entangling distant solid-state spins via thermal phonons, Phys. Rev. B 96, 245418 (2017) .

Link: https://journals.aps.org/prb/abstract/10.1103/PhysRevB.96.245418