@article {ISI:000417473700003,
title = {Chiral spin condensation in a one-dimensional optical lattice},
journal = {PHYSICAL REVIEW B},
volume = {96},
number = {21},
year = {2017},
month = {DEC 7},
pages = {214502},
publisher = {AMER PHYSICAL SOC},
type = {Article},
abstract = {We study a spinor (two-component) Bose gas confined in a one-dimensional double-valley optical lattice which has a double-well structure in momentum space. Based on field theory analysis, it is found that spinor bosons in the double-valley band may form a spin-charge mixed chiral spin quasicondensate under certain conditions. Our numerical calculations in a concrete p-flux triangular ladder system confirm the robustness of the chiral spin order against interactions and quantum fluctuations. This exotic atomic Bose-Einstein condensate exhibits spatially staggered spin loop currents without any charge dynamics despite the complete absence of spin-orbit coupling in the system, creating an interesting approach to atom spintronics. The entanglement entropy scaling allows us to extract conformal-field-theory central charge and establish the low-energy effective field theory for the chiral spin condensate as a two-component Luttinger liquid. Our predictions should be detectable in atomic experiments through spin-resolved time-of-flight techniques.}, \%\%Address = {ONE PHYSICS ELLIPSE, COLLEGE PK, MD 20740-3844 USA},
issn = {2469-9950},
doi = {10.1103/PhysRevB.96.214502},
author = {Wu, Ying-Hai and Li, Xiaopeng and S. Das Sarma}
}
@article {ISI:000391305600002,
title = {Intrinsic decoherence in isolated quantum systems},
journal = {PHYSICAL REVIEW B},
volume = {95},
number = {1},
year = {2017},
month = {JAN 4},
pages = {014202},
abstract = {We study the intrinsic, disorder-induced decoherence of an isolated quantum system under its own dynamics. Specifically, we investigate the characteristic time scale (i.e., the decoherence time) associated with an interacting many-body system losing the memory of its initial state. To characterize the erasure of the initial state memory, we define a time scale, the intrinsic decoherence time, by thresholding the gradual decay of the disorder-averaged return probability. We demonstrate the system-size independence of the intrinsic decoherence time in different models, and we study its dependence on the disorder strength. We find that the intrinsic decoherence time increases monotonically as the disorder strength increases in accordance with the relaxation of locally measurable quantities. We investigate several interacting spin (e.g., Ising and Heisenberg) and fermion (e.g., Anderson and Aubry-Andre) models to obtain the intrinsic decoherence time as a function of disorder and interaction strength.},
issn = {2469-9950},
doi = {10.1103/PhysRevB.95.014202},
author = {Wu, Yang-Le and Deng, Dong-Ling and Li, Xiaopeng and S. Das Sarma}
}
@article {ISI:000391851800003,
title = {Logarithmic entanglement lightcone in many-body localized systems},
journal = {PHYSICAL REVIEW B},
volume = {95},
number = {2},
year = {2017},
month = {JAN 10},
pages = {024202},
abstract = {We theoretically study the response of a many-body localized system to a local quench from a quantum information perspective. We find that the local quench triggers entanglement growth throughout the whole system, giving rise to a logarithmic lightcone. This saturates the modified Lieb-Robinson bound for quantum information propagation in many-body localized systems previously conjectured based on the existence of local integrals of motion. In addition, near the localization-delocalization transition, we find that the final states after the local quench exhibit volume-law entanglement. We also show that the local quench induces a deterministic orthogonality catastrophe for highly excited eigenstates, where the typical wave-function overlap between the pre- and postquench eigenstates decays exponentially with the system size.},
issn = {2469-9950},
doi = {10.1103/PhysRevB.95.024202},
author = {Deng, Dong-Ling and Li, Xiaopeng and Pixley, J. H. and Wu, Yang-Le and S. Das Sarma}
}
@article { ISI:000416024600002,
title = {Machine learning topological states},
journal = {PHYSICAL REVIEW B},
volume = {96},
number = {19},
year = {2017},
month = {NOV 22},
issn = {2469-9950},
doi = {10.1103/PhysRevB.96.195145},
author = {Deng, Dong-Ling and Li, Xiaopeng and S. Das Sarma}
}
@article {ISI:000404978900007,
title = {Many-body localization in incommensurate models with a mobility edge},
journal = {ANNALEN DER PHYSIK},
volume = {529},
number = {7},
year = {2017},
month = {JUL},
pages = {1600399},
publisher = {WILEY-V C H VERLAG GMBH},
type = {Review},
abstract = {We review the physics of many-body localization in models with incommensurate potentials. In particular, we consider one-dimensional quasiperiodic models with single-particle mobility edges. A conventional perspective suggests that delocalized states act as a thermalizing bath for the localized states in the presence of of interactions. However, contrary to this intuition there is evidence that such systems can display non-ergodicity. This is in part due to the fact that the delocalized states do not have any kind of protection due to symmetry or topology and are thus susceptible to localization. A study of such incommensurate models, in the non-interacting limit, shows that they admit extended, partially extended, and fully localized many-body states. Non-interacting incommensurate models cannot thermalize dynamically and remain localized upon the introduction of interactions. In particular, for a certain range of energy, the system can host a non-ergodic extended (i.e. metallic) phase in which the energy eigenstates violate the eigenstate thermalization hypothesis (ETH) but the entanglement entropy obeys volume-law scaling. The level statistics and entanglement growth also indicate the lack of ergodicity in these models. The phenomenon of localization and non-ergodicity in a system with interactions despite the presence of single-particle delocalized states is closely related to the so-called many-body proximity effect and can also be observed in models with disorder coupled to systems with delocalized degrees of freedom. Many-body localization in systems with incommensurate potentials (without single-particle mobility edges) have been realized experimentally, and we show how this can be modified to study the the effects of such mobility edges. Demonstrating the failure of thermalization in the presence of a single-particle mobility edge in the thermodynamic limit would indicate a more robust violation of the ETH.}, \%\%Address = {POSTFACH 101161, 69451 WEINHEIM, GERMANY},
issn = {0003-3804},
doi = {10.1002/andp.201600399},
author = {Deng, Dong-Ling and Ganeshan, Sriram and Li, Xiaopeng and Modak, Ranjan and Mukerjee, Subroto and Pixley, J. H.}
}
@article { ISI:000407549100005,
title = {Mobility edges in one-dimensional bichromatic incommensurate potentials},
journal = {PHYSICAL REVIEW B},
volume = {96},
number = {8},
year = {2017},
month = {AUG 14},
issn = {2469-9950},
doi = {10.1103/PhysRevB.96.085119},
author = {Li, Xiao and Li, Xiaopeng and S. Das Sarma}
}
@article {ISI:000401235900001,
title = {Quantum Entanglement in Neural Network States},
journal = {PHYSICAL REVIEW X},
volume = {7},
number = {2},
year = {2017},
month = {MAY 11},
abstract = {Machine learning, one of today{\textquoteright}s most rapidly growing interdisciplinary fields, promises an unprecedented perspective for solving intricate quantum many-body problems. Understanding the physical aspects of the representative artificial neural-network states has recently become highly desirable in the applications of machine-learning techniques to quantum many-body physics. In this paper, we explore the data structures that encode the physical features in the network states by studying the quantum entanglement properties, with a focus on the restricted-Boltzmann-machine (RBM) architecture. We prove that the entanglement entropy of all short-range RBM states satisfies an area law for arbitrary dimensions and bipartition geometry. For long-range RBM states, we show by using an exact construction that such states could exhibit volume-law entanglement, implying a notable capability of RBM in representing quantum states with massive entanglement. Strikingly, the neural-network representation for these states is remarkably efficient, in the sense that the number of nonzero parameters scales only linearly with the system size. We further examine the entanglement properties of generic RBM states by randomly sampling the weight parameters of the RBM. We find that their averaged entanglement entropy obeys volume-law scaling, and the meantime strongly deviates from the Page entropy of the completely random pure states. We show that their entanglement spectrum has no universal part associated with random matrix theory and bears a Poisson-type level statistics. Using reinforcement learning, we demonstrate that RBM is capable of finding the ground state (with power-law entanglement) of a model Hamiltonian with a long-range interaction. In addition, we show, through a concrete example of the one-dimensional symmetry-protected topological cluster states, that the RBM representation may also be used as a tool to analytically compute the entanglement spectrum. Our results uncover the unparalleled power of artificial neural networks in representing quantum many-body states regardless of how much entanglement they possess, which paves a novel way to bridge computer-science-based machine-learning techniques to outstanding quantum condensed-matter physics problems.},
issn = {2160-3308},
doi = {10.1103/PhysRevX.7.021021},
author = {Deng, Dong-Ling and Li, Xiaopeng and S. Das Sarma}
}
@article {ISI:000400371800001,
title = {Statistical bubble localization with random interactions},
journal = {PHYSICAL REVIEW B},
volume = {95},
number = {2},
year = {2017},
month = {JAN 24},
abstract = {We study one-dimensional spinless fermions with random interactions, but without any on-site disorder. We find that random interactions generically stabilize a many-body localized phase, in spite of the completely extended single-particle degrees of freedom. In the large randomness limit, we construct {\textquoteleft}{\textquoteleft}bubble-neck{{\textquoteright}{\textquoteright}} eigenstates having a universal area-law entanglement entropy on average, with the number of volume-law states being exponentially suppressed. We argue that this statistical localization is beyond the phenomenological local-integrals-of-motion description of many-body localization. With exact diagonalization, we confirm the robustness of the many-body localized phase at finite randomness by investigating eigenstate properties such as level statistics, entanglement/participation entropies, and nonergodic quantum dynamics. At weak random interactions, the system develops a thermalization transition when the single-particle hopping becomes dominant.},
issn = {2469-9950},
doi = {10.1103/PhysRevB.95.020201},
author = {Li, Xiaopeng and Deng, Dong-Ling and Wu, Yang-Le and S. Das Sarma}
}
@article { ISI:000382794800002,
title = {Detecting pi-phase superfluids with p-wave symmetry in a quasi-one-dimensional optical lattice},
journal = {PHYSICAL REVIEW A},
volume = {94},
number = {3},
year = {2016},
month = {SEP 2},
issn = {2469-9926},
doi = {10.1103/PhysRevA.94.031602},
author = {Liu, Bo and Li, Xiaopeng and Hulet, Randall G. and Liu, W. Vincent}
}
@article { ISI:000379648400004,
title = {Majorana spintronics},
journal = {PHYSICAL REVIEW B},
volume = {94},
number = {1},
year = {2016},
month = {JUL 14},
issn = {2469-9950},
doi = {10.1103/PhysRevB.94.014511},
author = {Liu, Xin and Li, Xiaopeng and Deng, Dong-Ling and Liu, Xiong-Jun and S. Das Sarma}
}
@article {ISI:000385398800001,
title = {Physics of higher orbital bands in optical lattices: a review},
journal = {REPORTS ON PROGRESS IN PHYSICS},
volume = {79},
number = {11},
year = {2016},
month = {NOV},
pages = {116401},
abstract = {The orbital degree of freedom plays a fundamental role in understanding the unconventional properties in solid state materials. Experimental progress in quantum atomic gases has demonstrated that high orbitals in optical lattices can be used to construct quantum emulators of exotic models beyond natural crystals, where novel many-body states such as complex Bose-Einstein condensates and topological semimetals emerge. A brief introduction of orbital degrees of freedom in optical lattices is given and a summary of exotic orbital models and resulting many-body phases is provided. Experimental consequences of the novel phases are also discussed.},
issn = {0034-4885},
doi = {10.1088/0034-4885/79/11/116401},
author = {Li, Xiaopeng and Liu, W. Vincent}
}
@article { ISI:000376908700003,
title = {Quantum nonergodicity and fermion localization in a system with a single-particle mobility edge},
journal = {PHYSICAL REVIEW B},
volume = {93},
number = {18},
year = {2016},
month = {MAY 31},
pages = {184204},
issn = {2469-9950},
doi = {10.1103/PhysRevB.93.184204},
author = {Li, Xiaopeng and Pixley, J. H. and Deng, Dong-Ling and Ganeshan, Sriram and S. Das Sarma}
}
@article { ISI:000372709600010,
title = {Topological phases via engineered orbital hybridization in noncentrosymmetric optical lattices},
journal = {PHYSICAL REVIEW A},
volume = {93},
number = {3},
year = {2016},
month = {MAR 23},
issn = {2469-9926},
doi = {10.1103/PhysRevA.93.033643},
author = {Liu, Bo and Li, Xiaopeng and Liu, W. Vincent}
}
@article {ISI:000355617100012,
title = {Damping of Long-Wavelength Collective Modes in Spinor Bose-Fermi Mixtures},
journal = {PHYSICAL REVIEW LETTERS},
volume = {114},
number = {22},
year = {2015},
month = {JUN 4},
pages = {225303},
issn = {0031-9007},
doi = {10.1103/PhysRevLett.114.225303},
author = {Pixley, J. H. and Li, Xiaopeng and S. Das Sarma}
}
@article {ISI:000355533300007,
title = {Exotic topological density waves in cold atomic Rydberg-dressed fermions},
journal = {NATURE COMMUNICATIONS},
volume = {6},
year = {2015},
month = {MAY},
pages = {7137},
issn = {2041-1723},
doi = {10.1038/ncomms8137},
author = {Li, Xiaopeng and S. Das Sarma}
}
@article { ISI:000365778900001,
title = {Exponential orthogonality catastrophe in single-particle and many-body localized systems},
journal = {PHYSICAL REVIEW B},
volume = {92},
number = {22},
year = {2015},
month = {DEC 3},
pages = {220201},
issn = {1098-0121},
doi = {10.1103/PhysRevB.92.220201},
author = {Deng, Dong-Ling and Pixley, J. H. and Li, Xiaopeng and S. Das Sarma}
}
@article { ISI:000363507300007,
title = {Many-Body Localization and Quantum Nonergodicity in a Model with a Single-Particle Mobility Edge},
journal = {PHYSICAL REVIEW LETTERS},
volume = {115},
number = {18},
year = {2015},
month = {OCT 28},
pages = {186601},
issn = {0031-9007},
doi = {10.1103/PhysRevLett.115.186601},
author = {Li, Xiaopeng and Ganeshan, Sriram and Pixley, J. H. and S. Das Sarma}
}
@article { ISI:000351735600010,
title = {Spontaneous Quantum Hall Effect in an Atomic Spinor Bose-Fermi Mixture},
journal = {PHYSICAL REVIEW LETTERS},
volume = {114},
number = {12},
year = {2015},
month = {MAR 27},
pages = {125303},
issn = {0031-9007},
doi = {10.1103/PhysRevLett.114.125303},
author = {Xu, Zhi-Fang and Li, Xiaopeng and Zoller, Peter and Liu, W. Vincent}
}
@article {2732,
title = {Striped ferronematic ground states in a spin-orbit-coupled $S=1$ Bose gas},
journal = {Phys. Rev. A},
volume = {91},
year = {2015},
month = {Feb},
pages = {023608},
doi = {10.1103/PhysRevA.91.023608},
url = {http://link.aps.org/doi/10.1103/PhysRevA.91.023608},
author = {Natu, Stefan S. and Li, Xiaopeng and Cole, William S.}
}
@article { ISI:000349871400005,
title = {Weyl Superfluidity in a Three-Dimensional Dipolar Fermi Gas},
journal = {PHYSICAL REVIEW LETTERS},
volume = {114},
number = {4},
year = {2015},
month = {JAN 28},
issn = {0031-9007},
doi = {10.1103/PhysRevLett.114.045302},
author = {Liu, Bo and Li, Xiaopeng and Yin, Lan and Liu, W. Vincent}
}
@article { ISI:000343029400003,
title = {Chiral superfluidity with p-wave symmetry from an interacting s-wave atomic Fermi gas},
journal = {NATURE COMMUNICATIONS},
volume = {5},
year = {2014},
month = {SEP},
issn = {2041-1723},
doi = {10.1038/ncomms6064},
author = {Liu, Bo and Li, Xiaopeng and Wu, Biao and Liu, W. Vincent}
}
@article { ISI:000338516100004,
title = {Cyclotron dynamics of interacting bosons in artificial magnetic fields},
journal = {PHYSICAL REVIEW B},
volume = {89},
number = {22},
year = {2014},
month = {JUN 23},
issn = {1098-0121},
doi = {10.1103/PhysRevB.89.224302},
author = {Li, Xiaopeng and S. Das Sarma}
}