Reducing collective quantum state rotation errors with reversible dephasing

  title={Reducing collective quantum state rotation errors with reversible dephasing},
  author={Kevin C Cox and Matthew A. Norcia and Joshua M. Weiner and Justin Gary Bohnet and James K. Thompson},
  journal={Applied Physics Letters},
We demonstrate that reversible dephasing via inhomogeneous broadening can greatly reduce collective quantum state rotation errors, and observe the suppression of rotation errors by more than 21 dB in the context of collective population measurements of the spin states of an ensemble of 2.1×105 laser cooled and trapped 87Rb atoms. The large reduction in rotation noise enables direct resolution of spin state populations 13(1) dB below the fundamental quantum projection noise limit. Further, the… 

Figures from this paper

Extreme spin squeezing in the steady state of a generalized Dicke model
We present a scheme to generate steady-state atomic spin squeezing in a cavity QED system using cavity-mediated Raman transitions to engineer effective atom-photon interactions, which include both
Spin-Wave Multiplexed Atom-Cavity Electrodynamics.
It is highlighted that the current experimental configuration allows rapid, interchangeable cavity coupling to 4 profiles with an overlap parameter of less than 10%, enough to demonstrate, for example, a quantum repeater network simulation in the cavity.


Conditional spin squeezing of a large ensemble via the vacuum Rabi splitting.
We use the vacuum Rabi splitting to perform quantum nondemolition measurements that prepare a conditionally spin squeezed state of a collective atomic psuedospin. We infer a 3.4(6) dB improvement in
Implementation of cavity squeezing of a collective atomic spin.
Deterministically generate states with up to 5.6(6) dB of metrologically relevant spin squeezing on the canonical 87Rb hyperfine clock transition, through 2 orders of magnitude in the effective interaction strength, without free parameters.
Detecting multiparticle entanglement of Dicke states.
The authors' criterion proves that a Dicke-like state using spin dynamics in a Bose-Einstein condensate contains at least genuine 28-particle entanglement, and infer a generalized squeezing parameter of -11.4(5)  dB.
14-Qubit entanglement: creation and coherence.
We report the creation of Greenberger-Horne-Zeilinger states with up to 14 qubits. By investigating the coherence of up to 8 ions over time, we observe a decay proportional to the square of the
General formalism for evaluating the impact of phase noise on Bloch vector rotations
Quantum manipulation protocols for quantum sensors and quantum computation often require many single-qubit rotations. However, the impact of phase noise in the field that performs the qubit rotations
Steady-state many-body entanglement of hot reactive fermions.
It is shown that two-component Fermi gases at ~μK temperatures naturally evolve, in the presence of reactive two-body collisions, into states with highly entangled (Dicke-type) spin wave functions.
Accurate microwave control and real-time diagnostics of neutral-atom qubits
Department of Physics and Astronomy, University of New Mexico,Albuquerque, NM 87131(Dated: November 21, 2008)We demonstrate accurate single-qubit control in an ensemble of atomic qubits trapped in an
Control of inhomogeneous quantum ensembles
Finding control fields (pulse sequences) that can compensate for the dispersion in the parameters governing the evolution of a quantum system is an important problem in coherent spectroscopy and
Entanglement generated by dissipation and steady state entanglement of two macroscopic objects.
An experiment where dissipation continuously generates entanglement between two macroscopic objects is reported on, achieved by engineering the dissipation using laser and magnetic fields and leading to robust event-readyEntanglement maintained for 0.04 s at room temperature.
Steady-state entanglement of two superconducting qubits engineered by dissipation
We present a scheme for the dissipative preparation of an entangled steady state of two superconducting qubits in a circuit quantum electrodynamics (QED) setup. Combining resonator photon loss—a