Controlling Decoherence Speed Limit of a Single Impurity Atom in a Bose–Einstein‐Condensate Reservoir

Abstract

The decoherence speed limit (DSL) of a single impurity atom immersed in a Bose-Einstein-condensed (BEC) reservoir when the impurity atom is in a double-well potential is studied. It is demonstrated how the DSL of the impurity atom can be manipulated by engineering the BEC reservoir and the impurity potential within experimentally realistic limits. It is shown that the DSL can be controlled by changing key parameters such as the condensate scattering length, the effective dimension of the BEC reservoir, and the spatial configuration of the double-well potential imposed on the impurity. The physical mechanisms of controlling the DSL at root of the spectral density of the BEC reservoir are uncovered.

Witnessing entanglement via the geometric phase in a impurity-doped Bose-Einstein condensate

“…In particular, it is one of fascinating problems in the field of quantum physics and quantum information to detect quantum entanglement of a micro-macro system [8][9][10][11][12][13][14][15][16][17][18][19][20][21]. The difficulties inherent in such a question are manifolds, and they are related not only to quantum decoherence induced by the surrounding environment [22][23][24][25][26][27][28][29][30][31][32], but also to a measurement precision sufficient to observe quantum effects at such macroscales.…”

“…A Bose-Einstein condensate (BEC) doped with impurities [33][34][35][36][37][38][39] provides an ideal platform for the study of micromicro and micro-macro entanglement where microscopic impurities meets a macroscopic matter, the BEC. As the interaction among Rydberg impurity atoms [40][41][42][43][44][45] can be tailored by electric fields and microwave fields [46,47] while the BEC allows for an extremely precise control of interatomic interactions by manipulating s-wave scattering length [48,49], they can build a precisely controllable micro-macro quantum systems [50].…”

Complementarity between micro-micro and micro-macro entanglement in a Bose–Einstein condensate with two Rydberg impurities

“…This endeavor could contribute to challenge the observability of quantum features at the macroscopic level, which is one of the very fascinating open problems in quantum physics. The difficulties inherent in such a question are manifolds, and they are related not only to quantum decoherence induced by the surrounding environment [15][16][17][18][19][20][21][22][23][24][25], but also to a measurement precision sufficient to observe quantum effects at such macroscales.…”

Tayloring Bose-Einstein condensate environments for a Rydberg impurity

“…BEC-phonon induced impurity decoherence has so far been mainly studied in the context of ground-state impurities of a minority species [7,16,17,[28][29][30][31][32][33][34], ions [35], or polaron formation [36]. For ground-state impurities, spectral densities such as derived here for Rydberg impurities were reported in [37].…”