Southwest Quantum Information and Technology

Generating non-classical states of motion using spontaneous emission

Presenting Author: Jason Twamley, Macquarie University
Contributing Author(s): Ben Baragiola (Royal Melbourne Institute for Technology)

The generation of non-classical states of motion of matter is interesting both from a fundamental quantum science viewpoint but also permits such non-classical quantum states as potential resources for various quantum tasks such as quantum teleportation, sensing, communication and computation. In this work, using the SLH formalism, we explore systems of two-level emitters which are initially excited and are motionally trapped and optically coupled to a 1D waveguide either directly or via optical cavities. The emitter suffers a motional recoil upon the emission of a photon and this entangles the motion of the emitter with the emitted photon pulse. We find that for an emitter either directly coupled to a 1D waveguide, or coupled within a Fabry-Perot type cavity defined within the waveguide, the emitter is left in a mixed motional state which is typically classical (i.e. possesses a Wigner function which is positive). Interestingly, we find situations, e.g. emitter in front of a mirror, where the emitter is left in a mixed but highly non-classical motional state. We hypothesize that such non-classicality can only be achieved if the atom can re-interact with the emitted photon field. We also discover subtleties in the application of the SLH formalism to situations where the photon field can become trapped in the optical network.

(Session 9a : Friday from 3:45pm-4:15pm)