内容：

In contrast to a single quantum bit, an oscillator can store multiple excitations and coherences provided one has the ability to generate and manipulate complex multi-photon states. We demonstrate multi-photon control 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 to allow simultaneous manipulation of hundreds of photons. With a toolset of conditional qubit-photon logic, we map an arbitrary qubit state to a superposition of coherent states, known as a 'cat state'. We create cat states as large as 111 photons and extend this protocol to create superpositions of up to four coherent states. This control creates a powerful interface between discrete and continuous variable quantum computation and could enable applications in metrology and quantum information processing.

人物介绍：