Optimal control of the silicon-based donor electron spin quantum computing

Abstract

We demonstrate how gradient ascent pulse engineering optimal control methods can be implemented on donor electron spin qubits in Si semiconductors with an architecture complementary to the original Kane's proposal. We focus on the high-fidelity controlled-NOT (CNOT) gate and explicitly find its digitized control sequences by optimizing its fidelity over the external controls of the hyperfine A and exchange J interactions. This high-fidelity CNOT gate has an error of about $10^{-6}$, below the error threshold required for fault-tolerant quantum computation, and its operation time of 100ns is about 3 times faster than 297ns of the proposed global control scheme. It also relaxes significantly the stringent distance constraint of two neighboring donor atoms of 10~20nm as reported in the original Kane's proposal to about 30nm in which surface A and J gates may be built with current fabrication technology. The effects of the control voltage fluctuations, the dipole-dipole interaction and the electron spin decoherence on the CNOT gate fidelity are also discussed.

4 figures, accepted as a Rapid Communication by Phys. Rev. A

References in corpus (7)

• Optimal Dynamical Decoherence Control of a Qubit
• Robust optimal quantum gates for Josephson charge qubits
• Time Optimal Unitary Operations
• The Fibonacci scheme for fault-tolerant quantum computation
• Time-optimal synthesis of unitary transformations in coupled fast and slow qubit system
• Equivalent qubit dynamics under classical and quantum noise
• Molecular orbital calculations of two-electron states for P donor solid-state spin qubits

Cited by in corpus (10)

• Silicon Quantum Electronics
• Exploring the trade-off between fidelity- and time-optimal control of quantum unitary transformations
• Optimal control for non-Markovian open quantum systems
• Optimal control of fast and high-fidelity quantum gates with electron and nuclear spins of a nitrogen-vacancy center in diamond
• Searching for quantum optimal controls in the presence of singular critical points
• Optimal control for fast and high-fidelity quantum gates in coupled superconducting flux qubits
• Searching for quantum optimal controls under severe constraints
• Optimal control of quantum gates in an exactly solvable non-Markovian open quantum bit system
• Dynamics of a driven spin coupled to an antiferromagnetic spin bath
• Higher-order protection of quantum gates: Hamiltonian engineering coordinated with dynamical decoupling