scholarly journals Out-of-Equilibrium Dynamics of the Bose-Hubbard Model

2013 ◽  
Vol 2013 ◽  
pp. 1-39 ◽  
Author(s):  
Malcolm P. Kennett
Keyword(s):  
Hubbard Model ◽  
Optical Lattice ◽  
Cold Atoms ◽  
Cold Atom ◽  
Future Directions ◽  
Experimental Realization ◽  
Equilibrium Dynamics ◽  
Open Questions ◽  
Quantum Quenches ◽  
Insulating Phase

The Bose-Hubbard model is the simplest model of interacting bosons on a lattice. It has recently been the focus of much attention due to the realization of this model with cold atoms in an optical lattice. The ability to tune parameters in the Hamiltonian as a function of time in cold atom systems has opened up the possibility of studying out-of-equilibrium dynamics, including crossing the quantum critical region of the model in a controlled way. In this paper, I give a brief introduction to the Bose Hubbard model, and its experimental realization and then give an account of theoretical and experimental efforts to understand out-of-equilibrium dynamics in this model, focusing on quantum quenches, both instantaneous and of finite duration. I discuss slow dynamics that have been observed theoretically and experimentally for some quenches from the superfluid phase to the Mott insulating phase and the picture of two timescales, one for fast local equilibration and another for slow global equilibration, that appears to characterize this situation. I also discuss the theoretical and experimental observation of the Lieb-Robinson bounds for a variety of quenches and the Kibble-Zurek mechanism in quenches from the Mott insulator to superfluid. I conclude with a discussion of open questions and future directions.

scholarly journals Thermoelectricity Modeling with Cold Dipole Atoms in Aubry Phase of Optical Lattice

2020 ◽  
Vol 10 (6) ◽  
pp. 2090
Author(s):  
Oleg Zhirov ◽  
José Lages ◽  
Dima Shepelyansky
Keyword(s):  
Thermoelectric Properties ◽  
Optical Lattice ◽  
Figure Of Merit ◽  
Cold Atoms ◽  
Periodic Potential ◽  
Cold Atom ◽  
Critical Amplitude ◽  
Dipole Interactions ◽  
Symplectic Map ◽  
A Chain

We study analytically and numerically the thermoelectric properties of a chain of cold atoms with dipole-dipole interactions placed in an optical periodic potential. At small potential amplitudes the chain slides freely that corresponds to the Kolmogorov-Arnold-Moser phase of integrable curves of a symplectic map. Above a certain critical amplitude the chain is pinned by the lattice being in the cantori Aubry phase. We show that the Aubry phase is characterized by exceptional thermoelectric properties with the figure of merit Z T = 25 being 10 times larger than the maximal value reached in material science experiments. We show that this system is well accessible for magneto-dipole cold atom experiments that opens new prospects for investigations of thermoelectricity.

scholarly journals String patterns in the doped Hubbard model

Science ◽  
2019 ◽  
Vol 365 (6450) ◽  
pp. 251-256 ◽  
Author(s):  
Christie S. Chiu ◽  
Geoffrey Ji ◽  
Annabelle Bohrdt ◽  
Muqing Xu ◽  
Michael Knap ◽  
...  
Keyword(s):  
Hubbard Model ◽  
Strongly Correlated Electrons ◽  
Cold Atom ◽  
Strongly Correlated ◽  
Many Body ◽  
Spin Order ◽  
Open Questions ◽  
Modern Physics ◽  
Many Body Systems ◽  
The Individual

Understanding strongly correlated quantum many-body states is one of the most difficult challenges in modern physics. For example, there remain fundamental open questions on the phase diagram of the Hubbard model, which describes strongly correlated electrons in solids. In this work, we realize the Hubbard Hamiltonian and search for specific patterns within the individual images of many realizations of strongly correlated ultracold fermions in an optical lattice. Upon doping a cold-atom antiferromagnet, we find consistency with geometric strings, entities that may explain the relationship between hole motion and spin order, in both pattern-based and conventional observables. Our results demonstrate the potential for pattern recognition to provide key insights into cold-atom quantum many-body systems.

Probing Bloch oscillations using a slow-light sensor

2020 ◽  
Vol 9 (5) ◽  
pp. 243-246
Author(s):  
Pei-Chen Kuan ◽  
Chang Huang ◽  
Shau-Yu Lan
Keyword(s):  
Phase Shift ◽  
Optical Lattice ◽  
Cold Atoms ◽  
Slow Light ◽  
Internal State ◽  
Electromagnetically Induced Transparency ◽  
Bloch Oscillations ◽  
Bloch Oscillation ◽  
Induced Transparency ◽  
Transparency Condition

AbstractWe implement slow-light under electromagnetically induced transparency condition to measure the motion of cold atoms in an optical lattice undergoing Bloch oscillation. The motion of atoms is mapped out through the phase shift of light without perturbing the external and internal state of the atoms. Our results can be used to construct a continuous motional sensor of cold atoms.

Cold atom interferometry for inertial sensing in the field

2020 ◽  
Vol 9 (5) ◽  
pp. 221-225
Author(s):  
Ravi Kumar ◽  
Ana Rakonjac
Keyword(s):  
High Precision ◽  
Cold Atoms ◽  
Cold Atom ◽  
Atom Interferometry ◽  
Precision Measurements ◽  
Inertial Sensing ◽  
Fundamental Physics ◽  
Recent Developments ◽  
Resource Exploration ◽  
Atom Interferometers

AbstractAtom interferometry is one of the most promising technologies for high precision measurements. It has the potential to revolutionise many different sectors, such as navigation and positioning, resource exploration, geophysical studies, and fundamental physics. After decades of research in the field of cold atoms, the technology has reached a stage where commercialisation of cold atom interferometers has become possible. This article describes recent developments, challenges, and prospects for quantum sensors for inertial sensing based on cold atom interferometry techniques.

scholarly journals Are Engaged Workaholics Protected against Job-Related Negative Affect and Anxiety before Sleep? A Study of the Moderating Role of Gender

2018 ◽  
Vol 15 (9) ◽  
pp. 1996 ◽  
Author(s):  
Paola Spagnoli ◽  
Cristian Balducci ◽  
Liliya Scafuri Kovalchuk ◽  
Francesco Maiorano ◽  
Carmela Buono
Keyword(s):  
Negative Affect ◽  
Work Engagement ◽  
Process Analysis ◽  
Future Directions ◽  
Open Questions ◽  
Heavy Work ◽  
Conditional Process Analysis ◽  
The Relationship ◽  
Moderating Role

Although the interplay between workaholism and work engagement could explain several open questions regarding the Heavy Work Investment (HWI) phenomenon, few studies have addressed this issue. Thus, with the purpose of filling this literature gap, the present study aimed at examining a model where job-related negative affect mediates the relationship between the interplay of workaholism and work engagement, and anxiety before sleep. Since gender could have a role in the way the interplay would impact on the theorized model, we also hypothesized a moderated role of gender on the specific connection concerning the interplay between workaholism and work engagement, in relation to job-related negative affect. Conditional process analysis was conducted on a sample of 146 participants, balanced for gender. Results supported the mediating model and indicated the presence of a moderated role of gender, such that engaged workaholic women reported significantly less job-related negative affect than disengaged workaholic women. On the contrary, the interplay between workaholism and work engagement did not seem significant for men. Results are discussed in light of the limitations and future directions of the research in this field, as well as the ensuing practical implications.

scholarly journals Biometric Systems De-Identification: Current Advancements and Future Directions

2021 ◽  
Vol 1 (3) ◽  
pp. 470-495
Author(s):  
Md Shopon ◽  
Sanjida Nasreen Tumpa ◽  
Yajurv Bhatia ◽  
K. N. Pavan Kumar ◽  
Marina L. Gavrilova
Keyword(s):  
Information Security ◽  
System Development ◽  
User Profile ◽  
Information Privacy ◽  
Biometric System ◽  
Comprehensive Overview ◽  
Future Directions ◽  
Behavioral Biometrics ◽  
Open Questions ◽  
Biometric Systems

Biometric de-identification is an emerging topic of research within the information security domain that integrates privacy considerations with biometric system development. A comprehensive overview of research in the context of authentication applications spanning physiological, behavioral, and social-behavioral biometric systems and their privacy considerations is discussed. Three categories of biometric de-identification are introduced, namely complete de-identification, auxiliary biometric preserving de-identification, and traditional biometric preserving de-identification. An overview of biometric de-identification in emerging domains such as sensor-based biometrics, social behavioral biometrics, psychological user profile identification, and aesthetic-based biometrics is presented. The article concludes with open questions and provides a rich avenue for subsequent explorations of biometric de-identification in the context of information privacy.

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