Year: 2019
Type: article
Abstract: Quantum error correction has recently emerged as a tool to enhance quantum sensing under Markovian noise. It works by correcting errors in a sensor while letting a signal imprint on the logical state. This approach typically requires a specialized error-correcting code, as most existing codes correct away both the dominant errors and the signal. To date, however, few such specialized codes are known, among which most require noiseless, controllable ancillas. We show here that such ancillas are not needed when the signal Hamiltonian and the error operators commute, a common limiting type of decoherence in quantum sensors. We give a semidefinite program for finding optimal ancilla-free sensing codes in general, as well as closed-form codes for two common sensing scenarios: qubits undergoing dephasing, and a lossy bosonic mode. Finally, we analyze the sensitivity enhancement offered by the qubit code under arbitrary spatial noise correlations, beyond the ideal limit of orthogonal signal and noise operators.
Source: Physical Review Letters
Institutions: Massachusetts Institute of Technology, Yale University
Language: English
Subfield: Artificial Intelligence
Field: Computer Science
Domain: Physical Sciences
Open Access status: bronze
Awards: G1234982065, G1482135624, G1523888516, G160464177, G165179637, G1657338961, G2598085392, G3067963855, G3392305090, G3663418429, G4211410756, G4591667967, G4645358078, G4746202754, G4835671942, G4911808732, G4962106257, G5327073570, G5385673730, G5488723185, Spectroscopy with Quantum Sensors at the Nanoscale, G5864310825, G6141599669, EFRI ACQUIRE: Scalable Quantum Communications with Error-Corrected Semiconductor Qubits, G657448715, G7452299184, G7500482128, G7900882, HYBRID QUANTUM SYSTEMS: SPINS, PHOTONS AND SUPERCONDUCTING QUBITS, G8535401926, G867139975, EFRI ACQUIRE: Integrated Nanophotonic Solid State Memories for Telecom Wavelength Quantum Repeaters
OpenAlex ID: W2898842402