title: Quantum Error-Correction-Enhanced Magnetometer Overcoming the Limit Imposed by Relaxation.
abstract: When incorporated in quantum sensing protocols, quantum error correction can be used to correct for high frequency noise, as the correction procedure does not depend on the actual shape of the noise spectrum. As such, it provides a powerful way to complement usual refocusing techniques. Relaxation imposes a fundamental limit on the sensitivity of state of the art quantum sensors which cannot be overcome by dynamical decoupling. The only way to overcome this is to utilize quantum error correcting codes. We present a superconducting magnetometry design that incorporates approximate quantum error correction, in which the signal is generated by a two qubit Hamiltonian term. This two-qubit term is provided by the dynamics of a tunable coupler between two transmon qubits. For fast enough correction, it is possible to lengthen the coherence time of the device beyond the relaxation limit.
authors.affiliation: Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Givat Ram, Israel.
authors.forename: David A
authors.initials: DA
authors.lastname: Herrera-Martí
authors.affiliation: Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Givat Ram, Israel.
authors.forename: Tuvia
authors.initials: T
authors.lastname: Gefen
authors.affiliation: School of Computer Science and Engineering, The Hebrew University, Jerusalem 91904, Israel.
authors.forename: Dorit
authors.initials: D
authors.lastname: Aharonov
authors.affiliation: Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Givat Ram, Israel.
authors.forename: Nadav
authors.initials: N
authors.lastname: Katz
authors.affiliation: Racah Institute of Physics, The Hebrew University of Jerusalem, Jerusalem 91904, Givat Ram, Israel.
authors.forename: Alex
authors.initials: A
authors.lastname: Retzker