7 papers
Overcoming decoherence of cat-states formed in a cavity using squeezed-state inputs
R. Y. Teh, P. D. Drummond, M. D. Reid
A cat-state is a superposition of two coherent states with amplitudes and . Recent experiments create cat states in a microwave cavity field using superconducting c…
Dynamics of transient cat-states in degenerate parametric oscillation with and without nonlinear Kerr interactions
R. Y. Teh, F. -X. Sun, R. E. S. Polkinghorne +4
A cat-state is formed as the steady-state solution for the signal mode of an ideal, degenerate parametric oscillator, in the limit of negligible single-photon signal loss. In the p…
Schrödinger cats and steady states in subharmonic generation with Kerr nonlinearities
Feng-Xiao Sun, Qiongyi He, Qihuang Gong +3
We discuss general properties of the equilibrium state of parametric down-conversion in superconducting quantum circuits with detunings and Kerr anharmonicities, in the strongly no…
Criteria to detect genuine multipartite entanglement using spin measurements
R. Y. Teh, M. D. Reid
We derive conditions in the form of inequalities to detect the genuine -partite entanglement of systems. The inequalities are expressed in terms of variances of spin operato…
Discrete time symmetry breaking in quantum circuits: exact solutions and tunneling
Feng-Xiao Sun, Qiongyi He, Qihuang Gong +3
We discuss general properties of discrete time quantum symmetry breaking in degenerate parametric oscillators. Recent experiments in superconducting quantum circuit with Josephson…
Quantum fidelity measures for mixed states
Yeong-Cherng Liang, Yu-Hao Yeh, Paulo E. M. F. Mendonça +3
Applications of quantum technology often require fidelities to quantify performance. These provide a fundamental yardstick for the comparison of two quantum states. While this is s…