Article
Physics, Multidisciplinary
Marcin Plodzien, Maciej Lewenstein, Emilia Witkowska, Jan Chwedenczuk
Summary: We demonstrate that one-axis twisting (OAT) is a powerful source of many-body Bell correlations for creating nonclassical states of bosonic qubits. We develop an analytical and universal treatment that allows us to identify the critical time for the emergence of Bell correlations and predict their depth at subsequent times. Our findings are illustrated using a highly nontrivial example of OAT dynamics generated with the Bose-Hubbard model.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Mohammadamin Tajik, Ivan Kukuljan, Spyros Sotiriadis, Bernhard Rauer, Thomas Schweigler, Federica Cataldini, Joao Sabino, Frederik Moller, Philipp Schuettelkopf, Si-Cong Ji, Dries Sels, Eugene Demler, Joerg Schmiedmayer
Summary: This experiment verifies the area law of quantum mutual information, which is one of the fundamental properties of equilibrium states of gapped quantum many-body systems. It also investigates the dependence of mutual information on temperature and the separation between subsystems.
Article
Multidisciplinary Sciences
K. J. Satzinger, Y-J Liu, A. Smith, C. Knapp, M. Newman, C. Jones, Z. Chen, C. Quintana, X. Mi, A. Dunsworth, C. Gidney, I Aleiner, F. Arute, K. Arya, J. Atalaya, R. Babbush, J. C. Bardin, R. Barends, J. Basso, A. Bengtsson, A. Bilmes, M. Broughton, B. B. Buckley, D. A. Buell, B. Burkett, N. Bushnell, B. Chiaro, R. Collins, W. Courtney, S. Demura, A. R. Derk, D. Eppens, C. Erickson, L. Faoro, E. Farhi, A. G. Fowler, B. Foxen, M. Giustina, A. Greene, J. A. Gross, M. P. Harrigan, S. D. Harrington, J. Hilton, S. Hong, T. Huang, W. J. Huggins, L. B. Ioffe, S. Isakov, E. Jeffrey, Z. Jiang, D. Kafri, K. Kechedzhi, T. Khattar, S. Kim, P. Klimov, A. N. Korotkov, F. Kostritsa, D. Landhuis, P. Laptev, A. Locharla, E. Lucero, O. Martin, J. R. McClean, M. McEwen, K. C. Miao, M. Mohseni, S. Montazeri, W. Mruczkiewicz, J. Mutus, O. Naaman, M. Neeley, C. Neill, M. Y. Niu, T. E. O'Brien, A. Opremcak, B. Pato, A. Petukhov, N. C. Rubin, D. Sank, V Shvarts, D. Strain, M. Szalay, B. Villalonga, T. C. White, Z. Yao, P. Yeh, J. Yoo, A. Zalcman, H. Neven, S. Boixo, A. Megrant, Y. Chen, J. Kelly, V Smelyanskiy, A. Kitaev, M. Knap, F. Pollmann, P. Roushan
Summary: The discovery of topological order revolutionized the understanding of quantum matter and laid the theoretical groundwork for quantum error-correcting codes. By preparing the ground state of the toric code Hamiltonian on a superconducting quantum processor, researchers were able to measure topological entanglement entropy and simulate anyon interferometry. Investigating aspects of the surface code, including logical state injection and the decay of nonlocal order parameter, showed the potential of quantum processors in studying topological quantum matter and error correction mechanisms.
Article
Optics
Sathyawageeswar Subramanian, Min-Hsiu Hsieh
Summary: A quantum algorithm is described to estimate the alpha-Renyi entropy of an unknown density matrix, using quantum singular value transformations and estimating normalized traces in a clean qubit model. The method outputs an estimate to additive precision epsilon using a certain number of quantum circuit applications, comparing favorably to traditional sample complexity models. Multiplicative approximations can also be obtained through an iterative process with logarithmic overhead in dimension d.
Article
Physics, Multidisciplinary
Pengfei Zhang, Zhenhua Yu
Summary: In closed generic many-body systems, the process of information scrambling, which disperses local quantum information into highly nonlocal objects, is quantified by the growth of operator size. However, the impact of couplings to the environment on this process remains unexplored. In this study, we predict a dynamical transition in quantum systems with all-to-all interactions accompanied by an environment, separating two phases: a dissipative phase where information scrambling halts and an operator size decays with time, and a scrambling phase where dispersion of information persists, the operator size grows and saturates in the long-time limit. Our prediction is derived from a general argument based on epidemiological models and demonstrated analytically via solvable Brownian Sachdev-Ye-Kitaev models. We also provide evidence that suggests this transition is generic to quantum chaotic systems when coupled to an environment.
PHYSICAL REVIEW LETTERS
(2023)
Article
Materials Science, Multidisciplinary
Yong-Yi Wang, Zheng-Hang Sun, Heng Fan
Summary: Recent research has shown a disorder-free many-body localization (MBL), known as Stark MBL, in an interacting system with a linear potential. The study investigates Stark MBL in two types of superconducting circuits and calculates entanglement entropy and participate entropy of highly excited eigenstates. The findings suggest that superconducting circuits are a promising platform for studying the critical properties of the Stark MBL transition.
Article
Quantum Science & Technology
Ryuji Takagi, Bartosz Regula, Mark M. Wilde
Summary: This study establishes a quantitative relation between the one-shot distillable resource yield and dilution cost, providing bounds applicable to different types of quantum resources and transformations. The results have broad applications in various research fields.
Article
Optics
Stefanie Czischek, Giacomo Torlai, Sayonee Ray, Rajibul Islam, Roger G. Melko
Summary: This study explores novel physics in circuit models involving entangling unitary dynamics and disentangling measurements. Using tensor network simulations, it reveals a transition from volume-law to area-law in entanglement entropy, suggesting universal features of a measurement-induced phase transition. The research highlights the robustness of this transition against experimental noise and emphasizes the role of tensor network simulations in advancing critical phenomena.
Article
Physics, Multidisciplinary
Thomas Schuster, Norman Y. Yao
Summary: In this study, a universal framework is provided to describe the scrambling of quantum information in open systems. It is predicted that the effect of open-system dynamics is fundamentally controlled by operator size distributions and independent of the microscopic error mechanism. This framework demonstrates that open quantum systems exhibit universal classes of information dynamics that fundamentally differ from their unitary counterparts.
PHYSICAL REVIEW LETTERS
(2023)
Article
Astronomy & Astrophysics
Ratchaphat Nakarachinda, Ekapong Hirunsirisawat, Lunchakorn Tannukij, Pitayuth Wongjun
Summary: This study investigates the possibility of achieving thermodynamic stability of the Schwarzschild-de Sitter black hole as an effective system using Renyi statistics. The results show that nonextensivity allows the black hole to be thermodynamically stable, with a lower bound on the nonextensive parameter. Comparisons with the separated system approach reveal that the thermodynamically stable black hole in the effective approach is larger than the one in the separated approach at certain temperatures, with only a zeroth-order phase transition observed in the effective system.
Article
Quantum Science & Technology
Tobias Haug, M. S. Kim
Summary: This study introduces an efficient method to measure the magic resource of pure quantum states, with a sampling cost that is independent of the number of qubits. We use Bell measurements to detect stabilizer and nonstabilizer states experimentally and propose a variational quantum algorithm to maximize our measure. Our results pave the way for understanding the nonclassical power of quantum computers, quantum simulators, and quantum many-body systems.
Article
Physics, Fluids & Plasmas
Piotr Bialas, Piotr Korcyl, Tomasz Stebel
Summary: We present a direct method for estimating the bipartite mutual information of a classical spin system using Monte Carlo sampling enhanced by autoregressive neural networks. The method allows for the study of arbitrary subsystem geometries and can be generalized to classical field theories. We demonstrate its applicability to the Ising model with four partitionings, including a multiply connected even-odd division. Our results show that the area law holds for temperatures away from the critical temperature, with a universal constant term and different proportionality coefficients for the even-odd partitioning.
Article
Optics
Junaid Ur Rehman, Seongjin Hong, Yong-Su Kim, Hyundong Shin
Summary: The proposed framework aims to obtain detectable capacity bounds for quantum channels by estimating state purity and utilizing the variational method to find optimal input states. This approach provides new upper and lower bounds on communication rates of quantum channels, and enables the estimation of important metrics such as quantum capacity for arbitrary channels.
Article
Physics, Fluids & Plasmas
Yan-Wei Dai, Xi-Hao Chen, Sam Young Cho, Huan-Qiang Zhou
Summary: We study the mutual information between two lattice blocks in one-dimensional infinite lattice systems using von Neumann entropies. By considering the q-state Potts model and spin-1/2 XY model numerically, we observe singular behaviors in block-block mutual information at critical points for quantum phase transitions. The study reveals a consistent power-law decaying behavior of mutual information between lattice blocks as the separation increases, providing insights into critical exponents and their relation with block-block correlation.
Article
Physics, Multidisciplinary
Minh C. Tran, Daniel K. Mark, Wen Wei Ho, Soonwon Choi
Summary: In conventional approaches, extracting arbitrary information from quantum states requires measurements in different bases, which may be challenging for current quantum devices. We propose a scalable protocol that utilizes the ergodic nature of quantum dynamics to efficiently extract physical properties without sophisticated controls. This protocol can be implemented in existing analog quantum simulation platforms.
Article
Physics, Multidisciplinary
Ali Mollabashi, Noburo Shiba, Tadashi Takayanagi, Kotaro Tamaoka, Zixia Wei
Summary: Pseudo-entropy, a quantity dependent on initial and final states, exhibits novel properties such as saturation behavior and non-positivity of difference compared to averaged entanglement entropy. It can serve as a new quantum order parameter, detecting whether states are in the same quantum phase or not. This was numerically observed in free-scalar field theories and the Ising spin chain.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Ibrahim Akal, Yuya Kusuki, Noburo Shiba, Tadashi Takayanagi, Zixia Wei
Summary: In this study, the time evolution of entanglement entropy in a two-dimensional conformal field theory with a moving mirror was calculated using holography. It was found that in a setup modeling Hawking radiation, entanglement entropy exhibits linear growth, which can be interpreted as the production of entangled pairs, while in a setup mimicking black hole formation and evaporation, the evolution follows the ideal Page curve. The gravity dual of the moving mirror model constructed via holography provides a concrete model to derive the Page curve for black hole radiation in the strong coupling regime of gravity.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Particles & Fields
Tadashi Takayanagi, Takahiro Uetoko
Summary: In this paper, a Chern-Simons gravity dual of a two dimensional conformal field theory on a manifold with boundaries, known as boundary conformal field theory (BCFT), is provided. The correct boundary action on the end of the world brane in the Chern-Simons gauge theory is determined, reproducing known results of the AdS/BCFT for the Einstein gravity. A prescription for calculating holographic entanglement entropy using Wilson lines extending from the AdS boundary to the end of the world brane is given, and a higher spin extension of the formulation is discussed.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Tatsuma Nishioka, Tadashi Takayanagi, Yusuke Taki
Summary: The paper introduces the concept of topological pseudo entropy and examines its applications in Chern-Simons gauge theory. It demonstrates the equivalence between topological pseudo entropy and interface entropy, and also finds that the topological interface entropy for rational CFTs has a contribution identical to the topological entanglement entropy on a torus.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Jan Boruch, Pawel Caputa, Dongsheng Ge, Tadashi Takayanagi
Summary: This work elaborates on the holographic description of path-integral optimization using Hartle-Hawking wave functions in Anti-de Sitter spacetimes in conformal field theories. It argues that maximizing the Hartle-Hawking wave function is equivalent to the path-integral optimization procedure in CFT. The study shows that metrics maximizing gravity wave functions in particular holographic geometries precisely match those derived in the path-integral optimization procedure for their dual CFT states.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Physics, Particles & Fields
Masamichi Miyaji, Tadashi Takayanagi, Tomonori Ugajin
Summary: The study investigates overlaps between regularized boundary states in conformal field theories using AdS/BCFT duality, finding that the overlaps are exponentially suppressed and h_(ab)^(min) = c/24 in pure AdS3 gravity. In higher dimensions, h_(ab)^(min) depends on the tensions of the branes. The off diagonal elements of inner products in holographic boundary states can be computed directly from on-shell gravity actions.
JOURNAL OF HIGH ENERGY PHYSICS
(2021)
Article
Astronomy & Astrophysics
Jyotirmoy Bhattacharya, Diptarka Das, Sayan Kumar Das, Ankit Kumar Jha, Moulindu Kundu
Summary: Researchers studied the effectiveness of numerical bootstrap techniques in quantum mechanical systems, finding correct capturing of non-perturbative aspects in a double well potential. Further investigation on quantum mechanical potentials related by supersymmetry revealed expected spectra recovery. In the singlet sector of O(N) vector model quantum mechanics, the bootstrap method yielded results consistent with saddle point analysis at large N.
Article
Physics, Particles & Fields
Taishi Kawamoto, Takato Mori, Yu-ki Suzuki, Tadashi Takayanagi, Tomonori Ugajin
Summary: We present a gravity dual model for local operator quench in a two-dimensional CFT with conformal boundaries. The model consists of a massive excitation in a three-dimensional AdS space and an end of the world brane, which undergoes nontrivial deformations due to gravitational backreaction. We show that the energy-momentum tensor and entanglement entropy computed from the gravity dual and from the BCFT in the large c limit perfectly match, elegantly avoiding the folding of the end of the world brane.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
Yasuaki Hikida, Tatsuma Nishioka, Tadashi Takayanagi, Yusuke Taki
Summary: We present a class of dS/CFT correspondence between two-dimensional CFTs and three-dimensional de Sitter spaces. We argue that this correspondence includes various gravity limits and dualities associated with SU(2) and SU(N) WZW models. We confirm the correctness of this correspondence and study two-point functions and entanglement entropy. We also discuss the possible spectrum and quantum corrections in the gravity theory.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Multidisciplinary
Yasuaki Hikida, Tatsuma Nishioka, Tadashi Takayanagi, Yusuke Taki
Summary: This letter proposes a holographic duality for classical gravity on a three-dimensional de Sitter space and presents evidence in terms of classical partition function and conformal field theory.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Particles & Fields
Kenta Suzuki, Tadashi Takayanagi
Summary: In this paper, we investigate the equivalence between a boundary conformal field theory (BCFT) and a gravitational system by studying its duality relation in a two-dimensional setup. By examining the computation of entanglement entropy and energy flux conservation, we identify the dual two-dimensional gravity to the boundary dynamics of a BCFT. Furthermore, we demonstrate that one point functions can be correctly reproduced in the AdS/BCFT by considering a gravity solution with scalar fields turned on.
JOURNAL OF HIGH ENERGY PHYSICS
(2022)
Article
Physics, Particles & Fields
Hiroki Kanda, Masahide Sato, Yu-ki Suzuki, Tadashi Takayanagi, Zixia Wei
Summary: In this paper, we investigate the dynamics of EOW branes in AdS using scalar fields, which provide a new gravity dual for CFTs on manifolds with boundaries. We find explicit solutions that correspond to boundary RG flows, as well as annulus-like or cone-like shaped EOW branes that require the presence of the scalar field. Moreover, we present a gravity dual for a CFT on a strip with different boundary conditions due to the scalar potential, resulting in a confinement/deconfinement-like transition depending on temperature and the scalar potential. Finally, we highlight the close relationship between this phase transition and the measurement-induced phase transition via a Wick rotation.
JOURNAL OF HIGH ENERGY PHYSICS
(2023)
Article
Astronomy & Astrophysics
Ibrahim Akal, Taishi Kawamoto, Shan-Ming Ruan, Tadashi Takayanagi, Zixia Wei
Summary: The black hole singularity is crucial for understanding Hawking's information paradox. By imposing a final state boundary condition on the spacelike singularity, the conflict between global spacetime analysis and unitarity can potentially be resolved. Inspired by the final state proposal, this study explores the impact of final state projection in two dimensional conformal field theories. The researchers calculate the time evolution under postselection and use the real part of pseudoentropy to estimate the average amount of quantum entanglement between the initial and final states. The results show a Page-curve-like behavior for this quantity.
Article
Physics, Multidisciplinary
Hugo A. Camargo, Lucas Hackl, Michal P. Heller, Alexander Jahn, Tadashi Takayanagi, Bennet Windt
Summary: This article analyzes the quantities for two intervals in the vacuum of free bosonic and Ising conformal field theories using the most general Gaussian purifications, providing a comprehensive comparison with existing results and identifying universal properties. It further discusses important subtleties in the setup, such as the massless limit of the free bosonic theory and the Hilbert space structure under the Jordan-Wigner mapping in the spin chain model of the Ising conformal field theory.
PHYSICAL REVIEW RESEARCH
(2021)
Article
Astronomy & Astrophysics
Jan Boruch, Pawel Caputa, Tadashi Takayanagi
Summary: This paper introduces a gravity dual description of path integral optimization in conformal field theories and discusses the equivalence between maximizing the Hartle-Hawking wave function and the path integral optimization procedure, as well as its application in various dimensions.
