Hardware-efficient autonomous quantum memory protection

Zaki Leghtas (1, 2) , Gerhard Kirchmair (2) , Brian Vlastakis (2) , Robert J. Schoelkopf (2) , Michel H. Devoret (2) , Mazyar Mirrahimi (1)

1 SISYPHE - SIgnals and SYstems in PHysiology & Engineering
2 Yale University [New Haven]

We propose to encode a quantum bit of information in a superposition of coherent states of an oscillator, with four different phases. Our encoding in a single cavity mode, together with a protection protocol, significantly reduces the error rate due to photon loss. This protection is ensured by an efficient quantum error correction scheme employing the nonlinearity provided by a single physical qubit coupled to the cavity. We describe in detail how to implement these operations in a circuit quantum electrodynamics system. This proposal directly addresses the task of building a hardware-efficient quantum memory and can lead to important shortcuts in quantum computing architectures.

Zaki Leghtas, Gerhard Kirchmair, Brian Vlastakis, Robert J. Schoelkopf, Michel H. Devoret, et al.. Hardware-efficient autonomous quantum memory protection. Physical Review Letters, 2013, 111, 5 p. ⟨10.1103/PhysRevLett.111.120501⟩. ⟨hal-00924534⟩