scholarly journals Quantum Simulations of Many-Body Systems with Ultra-Cold Atoms

2009 ◽  
Author(s):  
Mikhail Lukin ◽  
Eugene Demler
Keyword(s):  
Cold Atoms ◽  
Many Body ◽  
Quantum Simulations ◽  
Many Body Systems

scholarly journals Virial expansion coefficients in the unitary Fermi gas

2020 ◽  
Author(s):  
Shimpei Endo
Keyword(s):  
Recent Progress ◽  
Cold Atoms ◽  
Virial Coefficient ◽  
Fermi Gas ◽  
Virial Expansion ◽  
Strongly Correlated ◽  
Many Body ◽  
Unitary Fermi Gas ◽  
Expansion Coefficients ◽  
Many Body Systems

Virial expansion is widely used in cold atoms to analyze high temperature strongly correlated many-body systems. As the n-th order virial expansion coefficient can be accurately obtained by exactly solving up to n-body problems, the virial expansion offers a few-body approach to study strongly correlated many-body problems. In particular, the virial expansion has successfully been applied to unitary Fermi gas. We review recent progress of the virial expansion studies in the unitary Fermi gas, in particular the fourth order virial coefficient.

scholarly journals Applications of fidelity measures to complex quantum systems

2016 ◽  
Vol 374 (2069) ◽  
pp. 20150153 ◽  
Author(s):  
Sandro Wimberger
Keyword(s):  
Cold Atoms ◽  
Dimensional System ◽  
Many Body ◽  
Practical Applications ◽  
Dynamical Regimes ◽  
Many Body Systems ◽  
Fidelity Measures ◽  
The Stability ◽  
Low Dimensional ◽  
Quantum Motion

We revisit fidelity as a measure for the stability and the complexity of the quantum motion of single-and many-body systems. Within the context of cold atoms, we present an overview of applications of two fidelities, which we call static and dynamical fidelity, respectively. The static fidelity applies to quantum problems which can be diagonalized since it is defined via the eigenfunctions. In particular, we show that the static fidelity is a highly effective practical detector of avoided crossings characterizing the complexity of the systems and their evolutions. The dynamical fidelity is defined via the time-dependent wave functions. Focusing on the quantum kicked rotor system, we highlight a few practical applications of fidelity measurements in order to better understand the large variety of dynamical regimes of this paradigm of a low-dimensional system with mixed regular–chaotic phase space.

scholarly journals Observation of Bloch oscillations and Wannier-Stark localization on a superconducting quantum processor

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Xue-Yi Guo ◽  
Zi-Yong Ge ◽  
Hekang Li ◽  
Zhan Wang ◽  
Yu-Ran Zhang ◽  
...  
Keyword(s):  
Thermal Transport ◽  
Cold Atoms ◽  
Potential Gradient ◽  
Linear Potential ◽  
Single Shot ◽  
Many Body ◽  
Bloch Oscillations ◽  
Joint Measurement ◽  
Single Spin ◽  
Many Body Systems

AbstractThe Bloch oscillation (BO) and Wannier-Stark localization (WSL) are fundamental concepts about metal-insulator transitions in condensed matter physics. These phenomena have also been observed in semiconductor superlattices and simulated in platforms such as photonic waveguide arrays and cold atoms. Here, we report experimental investigation of BOs and WSL simulated with a 5-qubit programmable superconducting processor, of which the effective Hamiltonian is an isotropic XY spin chain. When applying a linear potential to the system by properly tuning all individual qubits, we observe that the propagation of a single spin on the chain is suppressed. It tends to oscillate near the neighborhood of their initial positions, which demonstrates the characteristics of BOs and WSL. We verify that the WSL length is inversely correlated to the potential gradient. Benefiting from the precise single-shot simultaneous readout of all qubits in our experiments, we can also investigate the thermal transport, which requires the joint measurement of more than one qubits. The experimental results show that, as an essential characteristic for BOs and WSL, the thermal transport is also blocked under a linear potential. Our experiment would be scalable to more superconducting qubits for simulating various of out-of-equilibrium problems in quantum many-body systems.

scholarly journals PT-symmetric non-Hermitian quantum many-body system using ultracold atoms in an optical lattice with controlled dissipation

2020 ◽  
Vol 2020 (12) ◽  
Author(s):  
Yosuke Takasu ◽  
Tomoya Yagami ◽  
Yuto Ashida ◽  
Ryusuke Hamazaki ◽  
Yoshihito Kuno ◽  
...  
Keyword(s):  
Optical Lattice ◽  
Ultracold Atoms ◽  
Cold Atoms ◽  
Experimental Setup ◽  
Body System ◽  
Many Body ◽  
System Parameters ◽  
Atom Loss ◽  
Many Body Systems ◽  
Important System

Abstract We report our realization of a parity–time (PT)-symmetric non-Hermitian many-body system using cold atoms with dissipation. After developing a theoretical framework on PT-symmetric many-body systems using ultracold atoms in an optical lattice with controlled dissipation, we describe our experimental setup utilizing one-body atom loss as dissipation with special emphasis on calibration of important system parameters. We discuss loss dynamics observed experimentally.

scholarly journals Quantum-optical magnets with competing short- and long-range interactions: Rydberg-dressed spin lattice in an optical cavity

2016 ◽  
Vol 1 (1) ◽  
Author(s):  
Jan Gelhausen ◽  
Michael Buchhold ◽  
Achim Rosch ◽  
Philipp Strack
Keyword(s):  
Quantum Optics ◽  
Long Range ◽  
Short Range ◽  
Cold Atoms ◽  
Theoretical Modelling ◽  
Many Body ◽  
Spin Lattice ◽  
Long Range Interactions ◽  
Many Body Systems ◽  
Quantum Optical

The fields of quantum simulation with cold atoms and quantum optics are currently being merged. In a set of recent pathbreaking experiments with atoms in optical cavities , lattice quantum many-body systems with both, a short-range interaction and a strong interaction potential of infinite range –mediated by a quantized optical light field– were realized. A theoretical modelling of these systems faces considerable complexity at the interface of: (i) spontaneous symmetry-breaking and emergent phases of interacting many-body systems with a large number of atoms N\rightarrow \inftyN→∞, (ii) quantum optics and the dynamics of fluctuating light fields, and (iii) non-equilibrium physics of driven, open quantum systems. Here we propose what is possibly the simplest, quantum-optical magnet with competing short- and long-range interactions, in which all three elements can be analyzed comprehensively: a Rydberg-dressed spin lattice coherently coupled to a single photon mode. Solving a set of coupled even-odd sublattice master equations for atomic spin and photon mean-field amplitudes, we find three key results. (R1): Superradiance and a coherent photon field appears in combination with spontaneously broken magnetic translation symmetry. The latter is induced by the short-range nearest-neighbor interaction from weakly admixed Rydberg levels. (R2): This broken even-odd sublattice symmetry leaves its imprint in the light via a novel peak in the cavity spectrum beyond the conventional polariton modes. (R3): The combined effect of atomic spontaneous emission, drive, and interactions can lead to phases with anomalous photon number oscillations. Extensions of our work include nano-photonic crystals coupled to interacting atoms and multi-mode photon dynamics in Rydberg systems.

Prospective Merger Between Car-Parrinello and Lattice Boltzmann Methods for Quantum Many-Body Simulations

2011 ◽  
Vol 9 (5) ◽  
pp. 1137-1151 ◽  
Author(s):  
Sauro Succi ◽  
Silvia Palpacelli
Keyword(s):  
Molecular Dynamics ◽  
Computational Efficiency ◽  
Lattice Boltzmann ◽  
Quantum Fluids ◽  
Ab Initio Molecular Dynamics ◽  
Many Body ◽  
Lattice Boltzmann Methods ◽  
Quantum Simulations ◽  
Speed Up ◽  
Many Body Systems

AbstractFormal analogies between the Car-Parrinello (CP) ab-initio molecular dynamics for quantum many-body systems, and the Lattice Boltzmann (LB) method for classical and quantum fluids, are pointed out. A theoretical scenario, whereby the quantum LB would be coupled to the CP framework to speed-up many-body quantum simulations, is also discussed, together with accompanying considerations on the computational efficiency of the prospective CP-LB scheme.

REGULAR STRUCTURE OF LOW-LYING STATES FOR ATOMIC NUCLEI UNDER RANDOM INTERACTIONS

2008 ◽  
Vol 17 (supp01) ◽  
pp. 304-317
Author(s):  
Y. M. ZHAO
Keyword(s):  
Ground State ◽  
Collective Motion ◽  
Regular Structure ◽  
Positive Parity ◽  
Many Body ◽  
Random Interactions ◽  
Atomic Nuclei ◽  
Many Body Systems

In this paper we review regularities of low-lying states for many-body systems, in particular, atomic nuclei, under random interactions. We shall discuss the famous problem of spin zero ground state dominance, positive parity dominance, collective motion, odd-even staggering, average energies, etc., in the presence of random interactions.

scholarly journals Emergence of a Renormalized 1/N Expansion in Quenched Critical Many-Body Systems

2021 ◽  
Vol 126 (11) ◽  
Author(s):  
Benjamin Geiger ◽  
Juan Diego Urbina ◽  
Klaus Richter
Keyword(s):  
Many Body ◽  
Many Body Systems

scholarly journals Continuous Phase Transition without Gap Closing in Non-Hermitian Quantum Many-Body Systems

2020 ◽  
Vol 125 (26) ◽  
Author(s):  
Norifumi Matsumoto ◽  
Kohei Kawabata ◽  
Yuto Ashida ◽  
Shunsuke Furukawa ◽  
Masahito Ueda
Keyword(s):  
Phase Transition ◽  
Continuous Phase ◽  
Many Body ◽  
Continuous Phase Transition ◽  
Many Body Systems ◽  
Gap Closing
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