Review
Physics, Multidisciplinary
Bowen Chen, Bartlomiej Czech, Zi-Zhi Wang
Summary: In this paper, we provide a pedagogical review of the application of concepts from quantum information theory and gravitational theory in the anti-de Sitter/conformal field theory correspondence. We introduce various concepts and techniques, and aim to give researchers a working knowledge in this field for initiating original projects.
REPORTS ON PROGRESS IN PHYSICS
(2022)
Article
Astronomy & Astrophysics
Alfredo Giambrone, Adolfo Guarino, Emanuel Malek, Henning Samtleben, Colin Sterckx, Mario Trigiante
Summary: We provide the first holographic evidence for the existence of a nonsupersymmetric conformal manifold resulting from exactly marginal but supersymmetry-breaking deformations. Specifically, we construct a 2-parameter nonsupersymmetric deformation of a supersymmetric AdS nongeometric background in type 1IB string theory. We prove the perturbative stability of the nonsupersymmetric backgrounds and their protection against various nonperturbative instabilities. Additionally, we argue that diffeomorphism symmetry safeguards our solutions against higher-derivative string corrections.
Article
Optics
Yao Ou, Qi Zhang, Guoxiang Huang
Summary: We propose a scheme for realizing the quantum reflection of single photons in a cold Rydberg atomic gas via electromagnetically induced transparency. By using stored gate photons, a deep and tunable attractive potential can be prepared. Such a scheme is promising for designing dispersion-type single-photon switches and can be used as a quantum device for observing the wave and particle natures of photons simultaneously.
Article
Astronomy & Astrophysics
Mohammad Javad Vasli, M. Reza Mohammadi Mozaffar, Komeil Babaei Velni, Mohammad Sahraei
Summary: In this study, we use holography to evaluate the reflected entropy in anisotropic boundary theories dual to nonrelativistic geometries. It is suggested that this quantity is proportional to the minimal area of the entanglement wedge cross section. By applying this prescription, we investigate the impact of anisotropy on reflected entropy and other holographic entanglement measures. We particularly focus on the discontinuous phase transition of this quantity in a symmetric configuration consisting of two disjoint strips.
Article
Quantum Science & Technology
Qing-Yuan Wu, Zhe Meng, Jia-Zhi Yang, An-Ning Zhang
Summary: In this study, we demonstrate that the quantum properties of holographic metasurfaces can be obtained through quantum state tomography and quantum process tomography. The theoretical output states derived from the estimated quantum process are in good agreement with the experimental output states, proving the effectiveness of our method. This work not only provides theoretical and experimental analysis for understanding the quantum properties of holographic metasurfaces, but also lays the foundation for their application in the quantum field.
NPJ QUANTUM INFORMATION
(2022)
Article
Physics, Multidisciplinary
Jorge Miguel-Ramiro, Ferran Riera-Sabat, Wolfgang Duer
Summary: This study introduces collective strategies for the efficient, local verification of ensembles of Bell pairs, reducing the number of entangled pairs that need to be measured and destroyed by utilizing initial information and noise transfer. The remaining states can be directly certified.
PHYSICAL REVIEW LETTERS
(2022)
Article
Astronomy & Astrophysics
Mir Afrasiar, Himanshu Chourasiya, Vinayak Raj, Gautam Sengupta
Summary: In this paper, we provide a substantive proof of the covariant proposal for holographic reflected entropy in CF Ts dual to non-static AdS geometries. Through explicit computations in the AdS(3)/C F T-2 scenario, we obtain the reflected entropy for time-dependent bipartite mixed states in CFT(1+1)s with a conserved charge dual to bulk rotating extremal and non-extremal BTZ black holes using the replica technique. Our results perfectly match the corresponding extremal entanglement wedge cross section for these bulk geometries in the literature, which serves as a significant consistency check for the proposal and its potential extension to higher-dimensional AdS/C F T scenario.
Article
Physics, Mathematical
Monica Jinwoo Kang, David K. Kolchmeyer
Summary: We reframe entanglement wedge reconstruction using the language of operator-algebra quantum error correction with infinite-dimensional physical and code Hilbert spaces. Von Neumann algebras are employed to characterize observables in a boundary subregion and its entanglement wedge. By assuming the reconstruction of infinite-dimensional von Neumann algebras for both the entanglement wedge and its complement in their respective boundary subregions, we demonstrate the equality of relative entropies measured with respect to the bulk and boundary observables. Moreover, we establish the converse by showing that if the relative entropies measured in an entanglement wedge and its complement are equal to those measured in their respective boundary subregions, entanglement wedge reconstruction is possible. Along the way, we find that the bulk and boundary modular operators act similarly on the code subspace, providing a well-defined notion of holographic relative entropy for holographic theories with well-defined entanglement wedges.
COMMUNICATIONS IN MATHEMATICAL PHYSICS
(2023)
Article
Quantum Science & Technology
S. Jansen, K. Goodenough, S. de Bone, D. Gijswijt, D. Elkouss
Summary: In this paper, we study a new class of quantum entanglement distillation protocols that utilize bilocal Clifford operations and a round of communication for distillation. We introduce tools to optimize these protocols using a commodity desktop computer. By exploiting the symmetries of the input states, we find circuits that achieve the highest fidelity with perfect operations and no decoherence for up to n = 8 copies of a Werner state. These results are based on a correspondence between distillation protocols and double cosets of the symplectic group, and improve upon previously known protocols.
Article
Physics, Particles & Fields
Yu Shi, Qiyuan Pan, Jiliang Jing
Summary: The holographic subregion complexity (HSC) and holographic entanglement entropy (HEE) can both be used as good probes of phase transitions in unbalanced holographic superconductors. However, there are certain conditions where it is difficult to observe the phase transition of the system using the HSC approach. The unbalance parameter has different effects on HSC, while HEE always increases as the unbalance parameter increases.
EUROPEAN PHYSICAL JOURNAL C
(2021)
Article
Physics, Multidisciplinary
Sarang Gopalakrishnan, Michael J. Gullans
Summary: With increasing postselection strength, a quantum system can undergo a spectral phase transition of the non-Hermitian Hamiltonian, where one phase retains a mixed state and develops volume-law entanglement, while the other phase approaches a unique pure state with low entanglement from an arbitrary initial state. The transition is identified with an exceptional point in the spectrum of the non-Hermitian Hamiltonian, where PT symmetry is spontaneously broken, and is characterized using exact diagonalization and an approximate mean-field theory.
PHYSICAL REVIEW LETTERS
(2021)
Article
Quantum Science & Technology
Bartosz Regula
Summary: In this paper, we develop two general approaches for characterising the manipulation of quantum states using probabilistic protocols. We provide a necessary condition for the existence of a physical transformation between quantum states using a recently introduced resource monotone based on the Hilbert projective metric. We also introduce a method for bounding achievable probabilities in resource transformations under resource-non-generating maps through convex optimisation problems. These approaches are useful in studying quantum entanglement distillation.
Article
Astronomy & Astrophysics
Sabyasachi Maulik, Harvendra Singh
Summary: The study of entanglement entropy on the boundary of the Lif(4)((2)) x S-1 x S-5 brane configuration reveals that the net entropy density of the first-order excitations is independent of the typical size of subsystems. This result is interpreted in the context of the first law of entanglement thermodynamics.
Article
Physics, Multidisciplinary
Hugo A. Camargo, Lucas Hackl, Michal P. Heller, Alexander Jahn, Bennet Windt
Summary: Using lattice techniques, we provide an elementary proof that the decay of both the entanglement of purification and reflected entropy is enhanced with respect to the mutual information behavior by a logarithm of the distance between the subregions. Additionally, we numerically compute the overall coefficients for these quantities of interest in the Ising spin chain at criticality and the related free fermion conformal field theory.
PHYSICAL REVIEW LETTERS
(2021)
Article
Astronomy & Astrophysics
Aiden B. Sheckler, Gerald A. Miller
Summary: Light-front wave functions are used in studying Bloom-Gilman duality and presenting expressions for structure functions. A specific two-parton model is defined, and resonance transition form factors are computed using these wave functions. However, evaluations show that the global and local duality sum rules are not satisfied within the given model.
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
Ibrahim Akal, Yuya Kusuki, Noburo Shiba, Tadashi Takayanagi, Zixia Wei
Summary: This paper extensively studies moving mirrors in conformal field theories using field theoretic and holographic methods, focusing on escaping, kink, and double escaping mirror models. The holographic entanglement entropy calculations show the ideal Page curve in the kink mirror model and an interesting phase transition in the double escaping mirror model. Discussions also include the interpretation of moving mirrors in terms of two dimensional Liouville gravity and the connection between quantum energy conditions and the time evolution of holographic entanglement entropy.
CLASSICAL AND QUANTUM GRAVITY
(2021)
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.
Article
Astronomy & Astrophysics
Yoshifumi Nakata, Tadashi Takayanagi, Yusuke Taki, Kotaro Tamaoka, Zixia Wei
Summary: A new quantity called pseudo-entropy is introduced in this paper as a generalization of entanglement entropy via postselection, with potential applications as order parameters in quantum many-body systems. The geometric computation of pseudo-entropy in the AdS/CFT correspondence is explored, along with its properties and classifications in qubit systems. Additionally, the quantum information theoretic meaning of pseudo-entropy in specific examples is discussed, as well as its calculation in various scenarios including the presence of local operator excitations in different CFT models.