Spin swap gate in the presence of qubit inhomogeneity in a double quantum dot

Abstract

We study theoretically the effects of qubit inhomogeneity on the quantum logic gate of qubit swap, which is an integral part of the operations of a quantum computer. Our focus here is to construct a robust pulse sequence for swap operation in the simultaneous presence of Zeeman inhomogeneity for quantum dot trapped electron spins and the finite-time ramp-up of exchange coupling in a double dot. We first present a geometric explanation of spin swap operation, mapping the two-qubit operation onto a single-qubit rotation. We then show that in this geometric picture a square-pulse-sequence can be easily designed to perform swap in the presence of Zeeman inhomogeneity. Finally, we investigate how finite ramp-up times for the exchange coupling $J$ negatively affect the performance of the swap gate sequence, and show how to correct the problems numerically.

arXiv commentpublished version

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Cited by in corpus (4)

• Two-qubit Gate of Combined Single Spin Rotation and Inter-dot Spin Exchange in a Double Quantum Dot
• Effect of electron-nuclear spin interactions on electron-spin qubits localized in self-assembled quantum dots
• Mutual information and swap operation in the two-qubit Heisenberg model with Dzyaloshinskii-Moriya anisotropic antisymmetric interaction
• Swap Action in a Solid-State Controllable Anisotropic Heisenberg Model