Readout of the atomtronic quantum interference device

Abstract

A Bose-Einstein condensate confined in ring shaped lattices interrupted by a weak link and pierced by an effective magnetic flux defines the atomic counterpart of the superconducting quantum interference device: the atomtronic quantum interference device (AQUID). In this paper, we report on the detection of current states in the system through a self-heterodyne protocol. Following the original proposal of the NIST and Paris groups, the ring-condensate many-body wave function interferes with a reference condensate expanding from the center of the ring. We focus on the rf-AQUID which realizes effective qubit dynamics. Both the Bose-Hubbard and Gross-Pitaevskii dynamics are studied. For the Bose-Hubbard dynamics, we demonstrate that the selfheterodyne protocol can be applied, but higher-order correlations in the evolution of the interfering condensates are measured to readout of the current states of the system. We study how states with macroscopic quantum coherence can be told apart analyzing the noise in the time of flight of the ring condensate.

Tunable quantum switcher and router of single atoms using localized artificial magnetic fields

“…In this case, the eigenstate and corresponding energy will retain their original forms as in Eqs. (16) and (17). Then,dispersive as E = ε σ − 2J cos k σ [see Fig.…”

“…The artificial tunability has made ultracold atoms an attractive platform for conducting research on quantum information processing [1][2][3][4] and high-precision instruments [5][6][7][8][9]. Integrating different cold atom systems together, one can possibly realize the scalable quantum network, with each quantum node being a cold atom subsystem, thus promoting the recent development of atomtronic devices [10][11][12][13][14][15][16][17][18][19]. However, reaching this destination demands the coherent manipulation of cold atom matter waves such that different nodes can be individually addressed for the effective communication of quantum signals.…”

Mesoscopic electron transport and atomic gases, a review of Frank W. J. Hekking's scientific work

“…8 bottom right). AQUIDs have been defining a very interesting line of investigations both for experiment and theory [129][130][131][132]. Observing macroscopic quantum coherence and coherent quantum phase slips in experiments would provide major breakthroughs both in mesoscopic and cold-atoms physics.…”

Exact results for persistent currents of two bosons in a ring lattice

“…Persistent currents have been of defining importance in mesoscopic physics [17]. Recently, persistent currents have been attracting upsurged interest, especially in the cold-atom community as they grant an enhanced flexibility and control over the physical conditions of the system [18][19][20][21][22][23][24][25][26][27][28][29][30].…”