Fault-Tolerant Computing With Biased-Noise Superconducting Qubits

Abstract

We present a universal scheme of pulsed operations for the IBM oscillator-stabilized flux qubit comprising the CPHASE gate, single-qubit preparations and measurements. Based on numerical simulations, we argue that the error rates for these operations can be as low as about .5% and that noise is highly biased, with phase errors being stronger than all other types of errors by a factor of nearly 10^3. In contrast, the design of a CNOT gate for this system with an error rate of less than about 1.2% seems extremely challenging. We propose a special encoding which exploits the noise bias allowing us to implement a logical CNOT gate where phase errors and all other types of errors have nearly balanced rates of about .4%. Our results illustrate how the design of an encoding scheme can be adjusted and optimized according to the available physical operations and the particular noise characteristics of experimental devices.

15 pages, 7 figures

References in corpus (5)

• Superconducting Circuits and Quantum Information
• Fault-tolerant quantum computation with high threshold in two dimensions
• Fault-tolerant quantum computation against biased noise
• Robust optimal quantum gates for Josephson charge qubits
• Efficient one- and two-qubit pulsed gates for an oscillator stabilized Josephson qubit

Cited by in corpus (2)

• Dynamically Error-Corrected Gates for Universal Quantum Computation
• Fault-tolerant quantum computation versus Gaussian noise