Vlastakis, Brian

Tuesday Sept 17, 2013
Time: 16:45
Place: ETH Science City, HPF G6
Host: Andreas Wallraff

Deterministically encoding quantum information in 100-photon Schrödinger cat states

Brian Vlastakis,
Yale University, New Haven, CT, USA

With a toolset of conditional qubit-photon quantum logic, we map a quantum bit to a superposition of coherent states, also known as a Schrödinger cat state. We achieve this using a superconducting transmon qubit coupled to a waveguide cavity resonator with a highly ideal off-resonant coupling. This dispersive interaction is much greater than decoherence rates and higher order non-linearities which allow simultaneous control of hundreds of photons. We map an arbitrary qubit state to cat states as large as 111 photons which we characterize using direct Wigner tomography. We also extend this protocol to create superpositions of up to four coherent states.