Identifying noise sources in quantum systems via multi-level noise spectroscopy
According to some embodiments, a method can identify and discriminate contributions from one or more noise sources using the multi-level structure of a quantum system with three or more levels. The method can include: preparing the quantum system in a predetermined state; applying one or more control signals to the quantum system; measuring values of one or more observables of the quantum system that quantify the quantum system's response to the noise sources and the one or more applied control signals; extracting noise spectra information associated with the noise sources from the measured values; and identifying contributions from the one or more noise sources based on the noise spectra information.
1. A method for identifying and discriminating contributions from one or more noise sources using the multi-level structure of a quantum system with three or more levels, the method comprising:
preparing the quantum system in a predetermined state;
applying one or more control signals to the quantum system;
measuring values of one or more observables of the quantum system that quantify the quantum system's response to the noise sources and the one or more applied control signals;
extracting noise spectra information associated with the noise sources from the measured values; and
identifying contributions from the one or more noise sources based on the noise spectra information.
2. The method of claim 1 , comprising:
improving performance of the quantum system based on the extracted noise spectra information and the identified contributions from the one or more noise sources.
3. The method of claim 1 , wherein the quantum system comprises a plurality of superconducting qubits.
4. The method of claim 3 , wherein the superconducting qubits include transmon or gatemon qubits.
5. The method of claim 1 , wherein the quantum system comprises at least one of:
a nuclear spin system,
an electron spin system,
a trapped-ion system,
a neutral-atom system, or
a superconducting circuit.
6. The method of claim 1 , wherein the one or more noise sources include at least two of:
flux noise,
charge noise, and
photon shot noise.
7. A system for identifying and discriminating contributions from one or more noise sources using the multi-level structure of a quantum system with three or more levels, the system comprising:
a signal generator configured to:
prepare the quantum system in a predetermined state, and
apply one or more control signals to the quantum system; and
a noise identification processor configured to:
measure values of one or more observables of the quantum system that quantify the quantum system's response to the noise sources and the one or more applied control signals;
extract noise spectra information associated with the noise sources from the measured values; and
identify contributions from the one or more noise sources based on the noise spectra information.
8. The system of claim 7 , wherein the quantum system comprises a plurality of superconducting qubits.
9. The system of claim 8 , wherein the superconducting qubits include transmon or gatemon qubits.
10. The system of claim 7 , wherein the quantum system comprises at least one of:
a nuclear spin system,
an electron spin system,
a trapped-ion system,
a neutral-atom system, or
a superconducting circuit.
11. The system of claim 7 , wherein the one or more noise sources include at least two of:
flux noise,
charge noise, and
photon shot noise.