Universal set of quantum gates for double-dot spin qubits with fixed interdot coupling

Abstract

We propose a set of universal gate operations for the singlet-triplet qubit realized by two electron spins in a double quantum dot, in the presence of a fixed inhomogeneous magnetic field. All gate operations are achieved by switching the potential offset between the two dots with an electrical bias, and do not require time-dependent control of the tunnel coupling between the dots. We analyze the two-electron dynamics and calculate the effective qubit rotation angle as a function of the applied electric bias. We present explicit gate sequences for single-qubit rotations about two orthogonal axes, and a CNOT gate sequence, completing the universal gate set.

5 pages, 4 figures; final version v2 (minor changes)

References in corpus (5)

• Single-shot readout of electron spin states in a quantum dot using spin-dependent tunnel rates
• Tunable effective g-factor in InAs nanowire quantum dots
• Ultra-long distance interaction between spin qubits
• Photon statistics from coupled quantum dots
• Coherent rotations of a single spin-based qubit in a single quantum dot at fixed Zeeman energy

Cited by in corpus (16)

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• Effects of different geometries on the conductance, shot noise and tunnel magnetoresistance of double quantum dots
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• One-step preparation of cluster states in quantum dot molecules
• Measurement, control, and decay of quantum-dot spins
• Exchange-controlled single-electron-spin rotations in quantum dots
• Phonon-assisted tunneling between singlet states in two-electron quantum dot molecules
• Dispersive Coupling Between the Superconducting Transmission Line Resonator and the Double Quantum Dots
• Coherent spin rotations in open driven double quantum dots
• Quantum Computation and Bell-state Measurement with Double-Dot Molecules
• Electrical measurement of a two-electron spin state in a double quantum dot
• Control of spin coherence in semiconductor double quantum dots
• Theory of spin qubits in nanostructures
• Eliminating interactions between non-neighboring qubits in the preparation of cluster states in quantum molecules
• Discrete quantum Fourier transform in coupled semiconductor double quantum dot molecules