Kyle Kawagoe and Michael Levin. 2020. “Microscopic definitions of anyon data.” Phys. Rev. B, 101, Pp. 115113. Publisher's Version
Andreas Elben, Richard Kueng, Hsin-Yuan Huang, Rick Van Bijnen, Christian Kokail, Marcello Dalmonte, Pasquale Calabrese, Barbara Kraus, John Preskill, Peter Zoller, and Benoît Vermersch. 2020. “Mixed-state entanglement from local randomized measurements.” arXiv:2007.06305. Publisher's VersionAbstract
We propose a method for detecting bipartite entanglement in a many-body mixed state based on estimating moments of the partially transposed density matrix. The estimates are obtained by performing local random measurements on the state, followed by post-processing using the classical shadows framework. Our method can be applied to any quantum system with single-qubit control. We provide a detailed analysis of the required number of experimental runs, and demonstrate the protocol using existing experimental data [Brydges et al, Science 364, 260 (2019)].
Nils-Eric Guenther, Richard Schmidt, Georg M. Bruun, Victor Gurarie, and Pietro Massignan. 2020. “Mobile impurity in a Bose-Einstein condensate and the orthogonality catastrophe.” arXiv:2004.07166.
Denis V. Vasilyev, Andrey Grankin, Mikhail A. Baranov, Lukas M. Sieberer, and Peter Zoller. 2020. “Monitoring Quantum Simulators via Quantum Non-Demolition Couplings to Atomic Clock Qubits.” arXiv:2006.00214. Publisher's VersionAbstract
We discuss monitoring the time evolution of an analog quantum simulator via a quantum non-demolition (QND) coupling to an auxiliary `clock' qubit. The QND variable of interest is the `energy' of the quantum many-body system, represented by the Hamiltonian of the quantum simulator. We describe a physical implementation of the underlying QND Hamiltonian for Rydberg atoms trapped in tweezer arrays using laser dressing schemes for a broad class of spin models. As an application, we discuss a quantum protocol for measuring the spectral form factor of quantum many-body systems, where the aim is to identify signatures of ergodic vs. non-ergodic dynamics, which we illustrate for disordered 1D Heisenberg and Floquet spin models on Rydberg platforms. Our results also provide the physical ingredients for running quantum phase estimation protocols for measurement of energies, and preparation of energy eigenstates for a specified spectral resolution on an analog quantum simulator.
Pranay Gorantla, Ho Tat Lam, Nathan Seiberg, and Shu-Heng Shao. 2020. “More Exotic Field Theories in 3+1 Dimensions.” arXiv:2007.04904.
Andreas Kruckenhauser, Lukas M. Sieberer, William G. Tobias, Kyle Matsuda, Luigi De Marco, Jun-Ru Li, Giacomo Valtolina, Ana Maria Rey, Jun Ye, Mikhail A. Baranov, and Peter Zoller. 2020. “Nanoscale-structured interactions and potential barriers for dipolar quantum gases.” arXiv:2001.11792. Publisher's VersionAbstract
We design dipolar quantum many-body Hamiltonians that will facilitate the realization of exotic quantum phases under the current experimental conditions achieved for polar molecules and magnetic atoms with large dipolar moments. The main idea is to modulate both two-body dipolar interactions and single-body potential barriers on a spatial scale of tens of nanometers to strongly enhance energy scales of engineered many-body systems. This new scheme greatly relaxes the requirement for low temperatures necessary for observing new quantum phases, especially in comparison to Hubbard Hamiltonians for regular optical lattices. For polar molecules, our approach builds on the use of microwave fields to couple rotational energy eigenstates in static electric fields with strong gradients. We illustrate this approach by demonstrating the orientation switching on the nanoscale for the induced electric dipole moment of a polar molecule. This configuration leads to the formation of interface bound states of fermionic molecules with binding energies far exceeding typical energy scales in current experiments. While the concepts are developed for polar molecules, many of the present ideas can be readily carried over to atoms with magnetic dipolar interactions.
J Kudler-Flam, H Shapourian, and S Ryu. 2020. “The negativity contour: a quasi-local measure of entanglement for mixed states.” SciPost Phys., 8, Pp. 63. Publisher's Version
Kyle Aitken, Changha Choi, and Andreas Karch. 2020. “New and old fermionic dualities from 3d bosonization.” Journal of High Energy Physics, 2020, Pp. 35.
Kasra Hejazi, Zhu-Xi Luo, and Leon Balents. 2020. “Noncollinear phases in moiré magnets.” Proceedings of the National Academy of Sciences, 117, Pp. 10721–10726.
Zhihuan Dong and T Senthil. 2020. “Non-commutative field theory and composite Fermi Liquids in some quantum Hall systems.” arXiv:2006.01282.
Dominic V Else, Ryan Thorngren, and T Senthil. 2020. “Non-Fermi liquids as ersatz Fermi liquids: general constraints on compressible metals.” arXiv preprint arXiv:2007.07896.
Yichen Xu, Hao Geng, Xiao-Chuan Wu, Chao-Ming Jian, and Cenke Xu. 2020. “Non-Landau Quantum Phase Transitions and nearly-Marginal non-Fermi Liquid.” J. Stat. Mech., 2007, Pp. 073102.
Hao Geng. 2020. “Non-local Entanglement and Fast Scrambling in De-Sitter Holography.” arXiv:2005.00021.
Michael Pretko, S. A. Parameswaran, and Michael Hermele. 2020. “Odd Fracton Theories, Proximate Orders, and Parton Constructions.” arXiv:2004.14393.
Hossein Dehghani, Zachary M. Raines, Victor M. Galitski, and Mohammad Hafezi. 2020. “Optical enhancement of superconductivity via targeted destruction of charge density waves.” Phys. Rev. B, 101, Pp. 224506. Publisher's Version
Dam Thanh Son, Mikhail Stephanov, and Ho-Ung Yee. 2020. “The phase diagram of ultra quantum liquids.” arXiv:2006.01156.
Colin Rylands, Yudan Guo, Benjamin L. Lev, Jonathan Keeling, and Victor Galitski. 2020. “Photon-Mediated Peierls Transition of a 1D Gas in a Multimode Optical Cavity.” Phys. Rev. Lett., 125, Pp. 010404. Publisher's Version
S. Barbarino, J. Yu, P. Zoller, and J. C. Budich. 2020. “Preparing Atomic Topological Quantum Matter by Adiabatic Nonunitary Dynamics.” Physical Review Letters, 124.Abstract
Motivated by the outstanding challenge of realizing lowerature states of quantum matter in synthetic materials, we propose and study an experimentally feasible protocol for preparing topological states such as Chern insulators. By definition, such (nonsymmetry protected) topological phases cannot be attained without going through a phase transition in a closed system, largely preventing their preparation in coherent dynamics. To overcome this fundamental caveat, we propose to couple the target system to a conjugate system, so as to prepare a symmetry protected topological phase in an extended system by intermittently breaking the protecting symmetry. Finally, the decoupled conjugate system is discarded, thus projecting onto the desired topological state in the target system. By construction, this protocol may be immediately generalized to the class of invertible topological phases, characterized by the existence of an inverse topological order. We illustrate our findings with microscopic simulations on an experimentally realistic Chern insulator model of ultracold fermionic atoms in a driven spin-dependent hexagonal optical lattice.
Oscar Randal-Williams, Lokman Tsui, and Xiao-Gang Wen. 2020. “Quantization of Chern-Simons topological invariants for H-type and L-type quantum systems.” arXiv:2008.02613.
Andrew C. Potter, J. T. Chalker, and Victor Gurarie. 2020. “Quantum Hall Network Models as Floquet Topological Insulators.” Phys. Rev. Lett., 125, Pp. 086601. Publisher's Version