Multiqubit spectroscopy of Gaussian quantum noise
Author(s)
Paz Silva, Gerardo
Norris, Leigh M.
Viola, Lorenza
Griffith University Author(s)
Year published
2017
Metadata
Show full item recordAbstract
We introduce multipulse quantum noise spectroscopy protocols for spectral estimation of the noise affecting
multiple qubits coupled to Gaussian dephasing environments including both classical and quantum sources. Our
protocols are capable of reconstructing all the noise auto- and cross-correlation spectra entering the multiqubit
dynamics, providing access, in particular, to the asymmetric spectra associated with nonclassical environments.
Our result relies on (i) an exact analytic solution for the reduced multiqubit dynamics that holds in the presence of
an arbitrary Gaussian environment and dephasing-preserving control; ...
View more >We introduce multipulse quantum noise spectroscopy protocols for spectral estimation of the noise affecting multiple qubits coupled to Gaussian dephasing environments including both classical and quantum sources. Our protocols are capable of reconstructing all the noise auto- and cross-correlation spectra entering the multiqubit dynamics, providing access, in particular, to the asymmetric spectra associated with nonclassical environments. Our result relies on (i) an exact analytic solution for the reduced multiqubit dynamics that holds in the presence of an arbitrary Gaussian environment and dephasing-preserving control; (ii) the use of specific timing symmetries, which allow for a frequency comb to be engineered for all filter functions of interest, and for the spectra to be related to experimentally accessible observables. We show that quantum spectra have distinctive dynamical signatures, which we explore in two paradigmatic open-system models describing spin and charge qubits coupled to bosonic environments. Complete noise spectroscopy is demonstrated numerically in a realistic setting consisting of two-exciton qubits coupled to a phonon bath. The estimated spectra allow us to accurately predict the exciton dynamics as well as extract the temperature and spectral density of the quantum environment.
View less >
View more >We introduce multipulse quantum noise spectroscopy protocols for spectral estimation of the noise affecting multiple qubits coupled to Gaussian dephasing environments including both classical and quantum sources. Our protocols are capable of reconstructing all the noise auto- and cross-correlation spectra entering the multiqubit dynamics, providing access, in particular, to the asymmetric spectra associated with nonclassical environments. Our result relies on (i) an exact analytic solution for the reduced multiqubit dynamics that holds in the presence of an arbitrary Gaussian environment and dephasing-preserving control; (ii) the use of specific timing symmetries, which allow for a frequency comb to be engineered for all filter functions of interest, and for the spectra to be related to experimentally accessible observables. We show that quantum spectra have distinctive dynamical signatures, which we explore in two paradigmatic open-system models describing spin and charge qubits coupled to bosonic environments. Complete noise spectroscopy is demonstrated numerically in a realistic setting consisting of two-exciton qubits coupled to a phonon bath. The estimated spectra allow us to accurately predict the exciton dynamics as well as extract the temperature and spectral density of the quantum environment.
View less >
Journal Title
Physical Review A
Volume
95
Issue
2
Subject
Quantum Physics not elsewhere classified