Monitoring Entanglement Evolution and Collective Quantum Dynamics

Abstract

We generalize a recently developed scheme for monitoring coherent quantum dynamics with good time-resolution and low backaction [Reuther et al., Phys. Rev. Lett. 102, 033602 (2009)] to the case of more complex quantum dynamics of one or several qubits. The underlying idea is to measure with lock-in techniques the response of the quantum system to a high-frequency ac field. We demonstrate that this scheme also allows one to observe quantum dynamics with many frequency scales, such as that of a qubit undergoing Landau-Zener transitions. Moreover, we propose how to measure the entanglement between two qubits as well as the collective dynamics of qubit arrays.

11 pages, 5 figures

References in corpus (14)

• Artificial Brownian motors: Controlling transport on the nanoscale
• Strong magnetic coupling of an ultracold gas to a superconducting waveguide cavity
• Amplitude Spectroscopy of a Solid-State Artificial Atom
• Gauging a quantum heat bath with dissipative Landau-Zener transitions
• Scalable superconducting qubit circuits using dressed states
• Low-frequency measurement of the tunneling amplitude in a flux qubit
• Quantum state preparation in circuit QED via Landau-Zener tunneling
• Landau-Zener tunnelling in dissipative circuit QED
• Coherence stabilization of a two-qubit gate by AC fields
• Fast quantum limited read-out of a superconducting qubit using a slow oscillator
• The information about the state of a qubit gained by a weakly coupled detector
• Entanglement creation in circuit QED via Landau-Zener sweeps
• Low frequency Rabi spectroscopy for a dissipative two-level system
• Time-Resolved Measurement of a Charge Qubit