Taylor Ray,  

Sponsor or Client: 

Title:

Controlling noise in quantum devices using phononic spectral hole burning

Abstract:

While quantum physics may enable powerful new forms of computation, noise has stifled our ability to realize this in practical applications. This noise is produced in part by so-called two-level tunneling states (TLSs).

TLSs are hypothesized to be atoms or a group of atoms that can occupy either of two configurations within a material. Similar to how an electron within an atom can jump between orbitals when stimulated by a photon, TLSs can jump between their two energy configurations by absorbing or emitting a microwave or a phonon. This process contributes to unwanted noise in the system, which is a problem for upcoming in nascent quantum technologies that seek to utilize long-lived microwave excitations (e.g., superconducting qubits).

However, two remarkable properties may enable the noise produced by TLSs to be controlled: (1) they simultaneously interact with microwaves and phonons, and (2) their absorption can be “saturated,” or sharply reduced when driven by electromagnetic or mechanical waves.

The two-time correlation function and corresponding power spectrum for the deviation of a TLS dipole moment, provide information about the noise generated in the system, and the optical Bloch equations give information about the quantum dynamics of these systems including effects from the driving acoustic field and phonons inherent to the system. Using these insights, we aim to predict how electromagnetic noise produced by TLSs can be controlled using intense mechanical waves.