title: Heisenberg-Limited Qubit Read-Out with Two-Mode Squeezed Light.
abstract: We show how to use two-mode squeezed light to exponentially enhance cavity-based dispersive qubit measurement. Our scheme enables true Heisenberg-limited scaling of the measurement, and crucially, it is not restricted to small dispersive couplings or unrealistically long measurement times. It involves coupling a qubit dispersively to two cavities and making use of a symmetry in the dynamics of joint cavity quadratures (a so-called quantum-mechanics-free subsystem). We discuss the basic scaling of the scheme and its robustness against imperfections, as well as a realistic implementation in circuit quantum electrodynamics.
authors.affiliation: Department of Physics, McGill University, 3600 rue University, Montreal, Quebec H3A 2T8, Canada.|Départment de Physique, Université de Sherbrooke, 2500 boulevard de l'Université, Sherbrooke, Québec J1K 2R1, Canada.
authors.forename: Nicolas
authors.initials: N
authors.lastname: Didier
authors.affiliation: Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
authors.forename: Archana
authors.initials: A
authors.lastname: Kamal
authors.affiliation: Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.|MIT Lincoln Laboratory, 244 Wood Street, Lexington, Massachusetts 02420, USA.
authors.forename: William D
authors.initials: WD
authors.lastname: Oliver
authors.affiliation: Départment de Physique, Université de Sherbrooke, 2500 boulevard de l'Université, Sherbrooke, Québec J1K 2R1, Canada.|Canadian Institute for Advanced Research, Toronto, Ontario M5G 1Z8, Canada.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Blais
authors.affiliation: Department of Physics, McGill University, 3600 rue University, Montreal, Quebec H3A 2T8, Canada.
authors.forename: Aashish A
authors.initials: AA
authors.lastname: Clerk