L. L. Salcedo
Upper and lower bounds are written down for the minimum information entropy in phase space of an antisymmetric wave function in any number of dimensions. Similar bounds are given when the wave function is restricted to belong to any of the proper subspaces of the Fourier transform operator.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
继续探索
We study the dynamical localization of cold atoms in Fermi accelerator both in position space and in momentum space. We report the role of classical phase space in the development of dynamical localization phenomenon. We provide set of experimentally assessable parameters to perform this work in laboratory.
We describe all the localization observables of a quantum particle in a one-dimensional box in terms of sequences of unit vectors in a Hilbert space. An alternative representation in terms of positive semidefinite complex matrices is furnished and the commutative localizations are singled out. As a consequence, we also get a vector sequence characterization of the covariant phase observables.
Noise sequences of infinite matrices associated with covariant phase and box localization observables are defined and determined. The canonical observables are characterized within the relevant classes of observables as those with asymptotically minimal or minimal noise, i.e., the noise tending to 0 or having the value 0.
We show that finite systems with conical intersections can exhibit spontaneous symmetry breaking which manifests itself in spatial localization of eigenstates. This localization has a geometric phase origin and is robust against variation of model parameters. The transition between localized and delocalized eigenstate regimes resembles a continuous phase transition. The localization slows down the low-energy quantum nuclear dynamics at zero and low temperatures.
Interaction of the internal states of an atom with spatially dependent standing-wave cavity field can impart position information of the atom passing through it leading to subwavelength atom localization. We recently demonstrated a new regime of atom localization [Sahrai {\it et al.}, Phys. Rev. A {\bf 72}, 013820 (2005)], namely sub-half-wavelength localization through phase control of electromagnetically induced transparency. This regime corresponds to extreme localization of atoms within a chosen half-wavelength region of the standing-wave cavity field. Here we present further investigation…
Entanglement phases and phase transitions in monitored free fermion system due to localizations
研究受监控自由费米系统中局部化对纠缠相及相变的影响，揭示测量与局部化共同作用下的纠缠相界特性。
We propose a feedback scheme to control the vibrational motion of a single trapped particle based on indirect measurements of its position. It results the possibility of a motional phase space uncertainty contraction, correponding to cool the particle close to the motional ground state.
We investigate coherent control of single particles held in a bipartite optical lattice via a combined high-frequency modulation. Our analytical results show that for the photon resonance case the quantum tunneling and dynamical localization depend on the phase difference between the modulation components, which leads to a different route of the coherent destruction of tunneling and a simple method for stabilizing the system to implement the directed transport. The results could be referable for manipulating the transport characterization of the similar tilted and shaken optical or solid-state…
Phase Space Localization and Approach to Thermal Equilibrium for a Class of Open Systems
利用量子态扩散（QSD）图像分析了有限温度环境中量子振子的演化。采用类似于文献[7]的处理方法，我们确定了相应的伊藤方程的定态解。我们证明了它们的全局稳定性和计算典型的时间尺度表征本地化过程。近似对角形式的密度矩阵的恢复使我们能够验证在长时间限制下的热平衡方法，我们评论QSD和退相干历史方法之间的联系。
We study a generalized Aubry-Andre model that obeys $\mathcal{PT}$-symmetry. We observe a robust $\mathcal{PT}$-symmetric phase with respect to system size and disorder strength, where all eigenvalues are real despite the Hamiltonian being non-hermitian. This robust $\mathcal{PT}$-symmetric phase can support an Anderson localization transition, giving a rich phase diagram as a result of the interplay between disorder and $\mathcal{PT}$-symmetry. Our model provides a perfect platform to study disorder-driven localization phenomena in a $\mathcal{PT}$-symmetric system.
We show that, by simple modifications of the usual three-level $Λ$-type scheme used for obtaining electromagnetically induced transparency (EIT), phase dependence in the response of the atomic medium to a weak probe field can be introduced. This gives rise to phase dependent susceptibility. By properly controlling phase and amplitudes of the drive fields we obtain variety of interesting effects. On one hand we obtain phase control of the group velocity of a probe field passing through medium to the extent that continuous tuning of the group velocity from subluminal to superluminal and back is …
Quantum chaos and semiclassical behavior in mushroom billiards II: Structure of quantum eigenstates and their phase space localization properties
研究Bunimovich蘑菇台球中本征态的相空间局域化，通过Poincaré-Husimi表示和熵度量发现混沌本征态局域化规律，并验证混合本征态分数随半经典参数幂律衰减符合PUSC原理。
We study quantum information scrambling, specifically the growth of Heisenberg operators, in large disordered spin chains using matrix product operator dynamics to scan across the thermalization-localization quantum phase transition. We observe ballistic operator growth for weak disorder, and a sharp transition to a phase with sub-ballistic operator spreading. The critical disorder strength for the ballistic to sub-ballistic transition is well below the many body localization phase transition, as determined from finite size scaling of energy eigenstate entanglement entropy in small chains. In …
The nonequilibrium real-time dynamics of electron coherence is explored in the quantum transport through the double-dot Aharonov-Bohm interferometers. We solve the exact master equation to find the exact quantum state of the device, from which the changes of the electron coherence through the magnetic flux in the nonequilibrium transport processes is obtained explicitly. We find that the relative phase between the two charge states of the double dot localizes to $\fracπ{2}$ or $-\fracπ{2}$ for all different magnetic flux. This nontrivial phase localization process can be manifested in the meas…
We explore the dynamics of non-interacting particles loaded into a phase-modulated one-dimensional lattice formed by laterally oscillating square barriers. Tuning the parameters of the driven unit cell of the lattice selected parts of the classical phase space can be manipulated in a controllable manner. We find superdiffusion in position space for all parameters regimes. A directed current of an ensemble of particles can be created through locally breaking the spatiotemporal symmetries of the time-driven potential. Magnitude and direction of the current are tunable. Several mechanisms for tra…
We study numerically the dynamics of excitons on discrete rings in the presence of static disorder. Based on continuous-time quantum walks we compute the time evolution of the Wigner function (WF) both for pure diagonal (site) disorder, as well as for diagonal and off-diagonal (site and transfer) disorder. In both cases, large disorder leads to localization and destroys the characteristic phase space patterns of the WF found in the absence of disorder.
Experimental realization of the complete seven-phase Anderson-localization landscape
通过设计含非均匀分布跳跃零点的准周期光子晶格，实验实现了扩展相、临界相、局域相及其所有共存相构成的七相安德森局域化景观，并观测了相变。
Chains of superconducting circuit devices provide a natural platform for studies of synthetic bosonic quantum matter. Motivated by the recent experimental progress in realizing disordered and interacting chains of superconducting transmon devices, we study the bosonic many-body localization phase transition using the methods of exact diagonalization as well as matrix product state dynamics. We estimate the location of transition separating the ergodic and the many-body localized phases as a function of the disorder strength and the many-body on-site interaction strength. The main difference be…
Statistics of phase space localization measures and quantum chaos in the kicked top model
本文通过 Husimi 函数分析 kicked top 模型相空间中本征态的局域化度量统计，发现其分布随系统从可积向混沌渡越发生剧变，且在完全混沌区普遍呈现 beta 分布，为诊断量子混沌提供了新视角。
Measuring the degree of localization of quantum states in phase space is essential for the description of the dynamics and equilibration of quantum systems, but this topic is far from being understood. There is no unique way to measure localization, and individual measures can reflect different aspects of the same quantum state. Here, we present a general scheme to define localization in measure spaces, which is based on what we call Rényi occupations, from which any measure of localization can be derived. We apply this scheme to the four-dimensional unbounded phase space of the interacting sp…
We investigate a uniformly coupled non-Hermitian system with asymmetric coupling amplitude. The asymmetric coupling equals to a symmetric coupling threaded by an imaginary gauge field. In a closed configuration, the imaginary gauge field leads to an imaginary magnetic flux, which induces a non-Hermitian phase transition. For an open boundary, the imaginary gauge field results in an eigenstate localization. The eigenstates under Dirac and biorthogonal norms and the scaling laws are quantitatively investigated to show the affect of asymmetric coupling induced one-way amplification. However, the …
When two independently-prepared Bose-Einstein condensates are released from their corresponding traps, the absorbtion image of the overlapping clouds presents an interference pattern. Here we analyze a model introduced by Javanainen and Yoo (J. Javanainen and S. M. Yoo, Phys. Rev. Lett. 76, 161 (1996)), who considered two atomic condensates described by plane waves propagating in opposite directions. We present an analytical argument for the measurement-induced breaking of the relative phase symmetry in this system, demonstrating how the phase gets localized after a large enough number of dete…
Phase-space localization at the lowest Landau level
本文研究谐振子势阱中弱相互作用玻色子在最低朗道能级上的相空间局域化，通过Husimi分布揭示相互作用解除简并后特定能级局域于低维曲面的现象。
We show that the presence of a harmonic trap may in itself lead to many-body localization for cold atoms confined in that trap in a quasi-one-dimensional geometry. Specifically, the coexistence of delocalized phase in the center of the trap with localized region closer to the edges is predicted with the borderline dependent on the curvature of the trap. The phenomenon, similar in its origin to Stark localization, should be directly observed with cold atomic species. We discuss both the spinless and the spinful fermions, for the latter we address Stark localization at the same time as it has no…
Algebraic localization-delocalization phase transition in moving potential wells on a lattice
本研究针对晶格上运动势阱因离散薛定谔方程伽利略不变性破缺导致的局域特性随速度变化的问题，揭示了无需无序的代数型局域-退局域相变，明确了不同幂律指数下的动力学行为，并提出了基于合成网格晶格的光子实验验证方案。
We investigate the localization and topological transitions in a one-dimensional (interacting) non-Hermitian quasiperiodic lattice, which is described by a generalized Aubry-André-Harper model with irrational modulations in the off-diagonal hopping and on-site potential and with non-Hermiticities from the nonreciprocal hopping and complex potential phase. For noninteracting cases, we reveal that the nonreciprocal hopping (the complex potential phase) can enlarge the delocalization (localization) region in the phase diagrams spanned by two quasiperiodical modulation strengths. We show that the …
Isolated quantum systems at strong disorder can display many-body localization (MBL), a remarkable phenomena characterized by an absence of conduction even at finite temperatures. As the ratio of interactions to disorder is increased, one expects that an MBL phase will eventually undergo a dynamical phase transition to a delocalized phase. Here we constrain the nature of such a transition by exploiting the strong subadditivity of entanglement entropy, as applied to the many-body eigenstates close to the transition in general dimensions. In particular, we show that at a putative continuous tran…
The Anderson localization transition is one of the most well studied examples of a zero temperature quantum phase transition. On the other hand, many open questions remain about the phenomenology of disordered systems driven far out of equilibrium. Here we study the localization transition in the prototypical three-dimensional, noninteracting Anderson model when the system is driven at its boundaries to induce a current carrying non-equilibrium steady state. Recently we showed that the diffusive phase of this model exhibits extensive mutual information of its non-equilibrium steady-state densi…
扫码添加微信好友，提出您的宝贵建议 👇
💡 备注请填写：网站反馈
发表机构由 AI 从论文文本抽取，如发现错误，欢迎反馈修正建议。