We propose a theoretical scheme for quantum sensing of temperature close to absolute zero in quasi-one-dimensional Bose-Einstein condensate (BEC). In our scheme, single-atom impurity qubit is used as sensor. investigate the sensitivity sensor estimating BEC. demonstrate that can saturate Cram\'er-Rao bound by means measuring coherence probe qubit. study performance using signal-to-noise ratio (QSNR). It indicated there an optimal encoding time at which QSNR reach its maximum full-temperature...

Abstract We investigate the possibility to control quantum evolution speed of a single dephasing qubit for arbitrary initial states by use periodic dynamical decoupling (PDD) pulses. It is indicated that limit time (QSLT) determined and final coherence qubit, as well non-Markovianity system under consideration during when subjected zero-temperature Ohmic-like reservoir. shown can be modulated PDD Our results show with non-vanishing coherence, pulses used induce potential acceleration in...

We study the energy structure and dynamics of a V-type three-level emitter embedded in one-dimensional waveguide with model dispersion. Due to presence two different couplings between upper levels modes, we find that bound states this system are quite from case two-level emitter. The is dependent on relative position emitter's transition frequencies band finite width. obtain phase diagrams through numerical analysis. spontaneous emission calculated exactly general by means Green's function...

We study the decoherence speed limit (DSL) of a single impurity atom immersed in Bose-Einsteincondensed (BEC) reservoir when is double-well potential. demonstrate how DSL can be manipulated by engineering BEC and potential within experimentally realistic limits. show that controlled changing key parameters such as condensate scattering length, effective dimension reservoir, spatial configuration imposed on impurity. uncover physical mechanisms controlling at root spectral density reservoir.

We present a new generalized Dicke model, an impurity-doped model (IDDM), by the use of cavity-Bose-Einstein condensate (BEC). It is shown that impurity atom can induce quantum phase transition (QPT) from normal to superradiant at critic value population. found impurity-induced QPT happen in arbitrary field-atom coupling regime while standard occurs only strong cavity field and atoms. This opens possibility realize control properties macroscopic-quantum system (BEC) using microscopic (a single atom).

This paper proposes an A* artificial intelligence pathfinding algorithm based on the hexagonal grid map of Unreal Engine 5. utilizes rich tools and resources provided by 5 to evaluate each node through a heuristic function, thus finding shortest path. Test results show that this not only can quickly find path, but also effectively avoid obstacle grids, with advantages such as high efficiency, flexibility, scalability. research result has practical value for solving problems maps provide...

In this paper, we investigate the effect of Dicke quantum phase transition on Berry two impurity qubits. The qubits only have dispersive interactions with optical field system. Therefore, do not affect ground state energy Hamiltonian. We find that has a sudden change at point. can be used as signal for transition. addition, differently near point different times. explain reason variations by studying variation parameters and time. Finally, investigated phases their initial conditions, found...

In this paper, we investigate how the evolution of states two qubits initially in a direct product state can be controlled by optical field Tavis-Cummings (TC) model. For state, find that their matrix elements at any moment modulated coefficients initial number space. We propose method for preparing an \textit{X}-type qubits. Subsequently, descriptive convenience, divide Bell into kinds paper. When both are ground to produce first type superposition is next-nearest-neighbor and production...

This paper studies the effect of single-photon light fields on quantum entanglement between two qubits and multiple identical initially in a direct state. For qubits, we first analyze impact excited state's weight single-photon-triggered entanglement, finding that excessive disrupts this process. We then explore how initial coherence affects discovering maximum enables single photon to achieve maximal entanglement. similarly investigate effects control. In large qubit systems, find photons...

We examine a system in which an impurity qubit is immersed quasi-two-dimensional dipolar Bose-Einstein condensate whose collective excitations act as depasing reservoir for the qubit. The relative dipole-dipole interaction strength estimated by probe dephasing. ultimate precision of this estimation quantified quantum Fisher information, can be obtained means measuring coherence Our findings indicate that, interval where roton appear, information oscillates periodically with encoding time...

We investigate the non-Markovianity (NM) of a waveguide QED with two-level atom as system and semi-infinite rectangular environment, where transverse magnetic (TM mn ) modes define quantum channels guided photons. The perfect mirror imposed by finite end exerts retarded feedback mechanism to allow for information backflow, which leads NM dynamics. For energy separation far away from cutoff frequencies modes, delay differential equations are obtained single-excitation initial in atom. Our...

The single-photon scattering in a rectangular waveguide by V-type three-level emitter is studied for large range of input-photon energy beyond the single-mode region. By using Lippmann-Schwinger formalism, necessary and sufficient conditions complete transmission reflection are derived analytically. In region, caused electromagnetically induced transparency (EIT) due to Fano resonance can both be achieved adjusting emitter's parameters. But multi-mode except that input-state prepared...

In this paper, we investigate the effect of Dicke quantum phase transition on speed evolution system dynamics. At point, symmetry associated with parity operator begins to break down. By comparing magnitudes two types limit times, find that time is described by one whether in normal or superradiant phase. We that, phase, strength coupling between optical field and atoms has little dynamical system. However, a stronger atom–photon can accelerate dynamics’ evolution. Finally, entanglement...

We present a method to accelerate the dynamical evolution of multiqubit open system by employing decoupling pulses (DDPs) when qubits are initially in W-type states. It is found that this speed-up can be achieved both weak-coupling regime and strong-coupling regime. The physical mechanism behind acceleration explained as result joint action non-Markovianity reservoirs excited-state population qubits. shown controlled DDPs realize quantum speed-up.

We present a new generalized Dicke model, an impurity-doped model (IDDM), by the use of cavity-Bose-Einstein condensate. It is shown that impurity atom can induce quantum phase transition (QPT) from normal to superradiant at critic value population. found IDDM exhibits continuous QPT with infinite number critical points, which significantly different observed in standard only one point. revealed impurity-induced happen arbitrary coupling regime cavity field and atoms while occurs strong...

We investigate the utilization of a single generalized dephasing qubit for sensing quantum reservoir, where antisymmetric coupling between and its reservoir is broken. It found that in addition to decay factor encoding channel, breaking gives rise another phase channel. introduce an optimal measurement which enables practical precision reach theoretical ultimate quantified by signal-to-noise ratio (QSNR). As example, employed estimate $s$-wave scattering length atomic Bose-Einstein...

In article number 1800423, Ya-Ju Song and Le-Man Kuang study the decoherence speed limit (DSL) of an impurity trapped in a double-well interacting with Bose-Einstein-condensed (BEC) reservoir. They found DSL can be controlled by changing BEC scattering length, effective dimension, well spacing depth. The regulation mechanism is also analyzed at root spectral density.

We propose a theoretical scheme for quantum sensing of temperature close to absolute zero in quasi-one-dimensional Bose-Einstein condensate (BEC). In our scheme, single-atom impurity qubit is used as temper-ature sensor. investigate the sensitivity sensor estimating BEC. demonstrate that can saturate Cramer-Rao bound by means measuring coherence probe qubit. study performance use signal-to-noise ratio (QSNR). It indicated there an optimal encoding time QSNR reach its maximum full-temperature...