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Chinese Physics Letters

Quantum Computing via Singlet-Triplet Spin Qubits in Nanowire Double Quantum Dots

Peng Xue

Published Jul 1, 2011• 5 citations
Publisher

Abstract

We propose a new structure for quantum computing via spin qubits with high fidelity. Each spin qubit corresponds to two electrons in a nanowire double quantum dot, with the singlet and one of the triplets as the logical qubit states. The entangling gate is effected by virtual charge dipole transitions. We include noise to show the feasibility of this scheme under current experimental conditions.

DOI
10.1088/0256-307x/28/7/070305

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We propose a new structure for quantum computing via spin qubits with high fidelity. Each spin qubit corresponds to two electrons in a nanowire double quantum dot, with the singlet and one of the triplets as the logical qubit states. The entangling gate is effected by virtual charge dipole transitions. We include noise to show the feasibility of this scheme under current experimental conditions.
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A logical qubit based on electron-spin singlet-triplet states in a semiconductor double dot has emerged as one of the promising candidates for quantum information processing. Here we propose a systematic method to implement rapid quantum gates in the nanosecond time scale for both a single qubit and multiqubits, by applying adiabatic driving pulses with tunable velocity. This yields considerable high-fidelity gate operations reaching 99.999.9%99.9 which are crucial to scalable quantum computation in a semiconductor-based architecture, even considering the demanding experimental constraints and realistic spin and charge noises.
We present a method for implementing universal quantum computing using a singlet and triplets of nanowire double quantum dots coupled to a one-dimensional transmission line resonator. This method is suitable and of interest for both quantum computing and quantum control with inhibition of spontaneous emission, enhanced spin qubit lifetime, strong coupling and quantum nondemolition measurements of spin qubits. We analyze the performance and stability of all the required operations and emphasize that all techniques are feasible with current experimental technology.
Abstract We propose an alternative scheme for one-step implementing three-qubit controlled phase-flip gate of spin qubits in spatially separated double quantum dots with a superconducting stripline resonator (SSR). Due to the switchable coupling effect between the double quantum dots and SSR, the present scheme could be easily generalized for multi-qubits. The feasibility of the present scheme is characterized by exact numerical simulations that incorporate various sources of experimental noise. Our results show the possibility to realize this proposed scheme within current experimental technologies.