80 citations · 457 across the 18 of their papers we have counts for
18 papers
On the generic increase of observational entropy in isolated systems
Teruaki Nagasawa, Kohtaro Kato, Eyuri Wakakuwa +1
Observational entropy -- a quantity that unifies Boltzmann's entropy, Gibbs' entropy, von Neumann's macroscopic entropy, and the diagonal entropy -- has recently been argued to pla…
Exact and local compression of quantum bipartite states
Kohtaro Kato
We study exact local compression of a quantum bipartite state; that is, applying local quantum operations to reduce the dimensions of the Hilbert spaces while perfectly preserving…
Universal validity of the second law of information thermodynamics
Shintaro Minagawa, M. Hamed Mohammady, Kenta Sakai +2
Adiabatic measurements, followed by feedback and erasure protocols, have often been considered as a model to embody Maxwell's Demon paradox and to study the interplay between therm…
Modular commutator in gapped quantum many-body systems
Isaac H. Kim, Bowen Shi, Kohtaro Kato +1
In arXiv:2110.06932, we argued that the chiral central charge -- a topologically protected quantity characterizing the edge theory of a gapped (2+1)-dimensional system -- can be ex…
Chiral central charge from a single bulk wave function
Isaac H. Kim, Bowen Shi, Kohtaro Kato +1
A -dimensional gapped quantum many-body system can have a topologically protected energy current at its edge. The magnitude of this current is determined entirely by the tem…
Matrix Product Density Operators: when do they have a local parent Hamiltonian?
Chi-Fang Chen, Kohtaro Kato, Fernando G. S. L. Brandão
We study whether one can write a Matrix Product Density Operator (MPDO) as the Gibbs state of a quasi-local parent Hamiltonian. We conjecture this is the case for generic MPDO and…
Symmetry-protected sign problem and magic in quantum phases of matter
Tyler D. Ellison, Kohtaro Kato, Zi-Wen Liu +1
We introduce the concepts of a symmetry-protected sign problem and symmetry-protected magic to study the complexity of symmetry-protected topological (SPT) phases of matter. In par…
Deformations of the Boundary Theory of the Square Lattice AKLT Model
John Martyn, Kohtaro Kato, Angelo Lucia
The 1D AKLT model is a paradigm of antiferromagnetism, and its ground state exhibits symmetry-protected topological order. On a 2D lattice, the AKLT model has recently gained atten…
Toy model of boundary states with spurious topological entanglement entropy
Kohtaro Kato, Fernando G. S. L. Brandão
Topological entanglement entropy has been extensively used as an indicator of topologically ordered phases. We study the conditions needed for two-dimensional topologically trivial…
Clustering of conditional mutual information for quantum Gibbs states above a threshold temperature
Tomotaka Kuwahara, Kohtaro Kato, Fernando G. S. L. Brandão
We prove that the quantum Gibbs states of spin systems above a certain threshold temperature are approximate quantum Markov networks, meaning that the conditional mutual informatio…
Macroscopic Thermodynamic Reversibility in Quantum Many-Body Systems
Philippe Faist, Takahiro Sagawa, Kohtaro Kato +2
The resource theory of thermal operations, an established model for small-scale thermodynamics, provides an extension of equilibrium thermodynamics to nonequilibrium situations. On…
Asymptotic Reversibility of Thermal Operations for Interacting Quantum Spin Systems via Generalized Quantum Stein's Lemma
Takahiro Sagawa, Philippe Faist, Kohtaro Kato +3
For quantum spin systems in any spatial dimension with a local, translation-invariant Hamiltonian, we prove that asymptotic state convertibility from a quantum state to another one…
Fusion rules from entanglement
Bowen Shi, Kohtaro Kato, Isaac H. Kim
We derive some of the axioms of the algebraic theory of anyon [A. Kitaev, Ann. Phys., 321, 2 (2006)] from a conjectured form of entanglement area law for two-dimensional gapped sys…
An entropic invariant for 2D gapped quantum phases
Kohtaro Kato, Pieter Naaijkens
We introduce an entropic quantity for two-dimensional (2D) quantum spin systems to characterize gapped quantum phases modeled by local commuting projector code Hamiltonians. The de…
Locality of Edge States and Entanglement Spectrum from Strong Subadditivity
Kohtaro Kato, Fernando G. S. L. Brandao
We consider two-dimensional states of matter satisfying an uniform area law for entanglement. We show that the topological entanglement entropy is equal to the minimum relative ent…
Quantum Approximate Markov Chains are Thermal
Kohtaro Kato, Fernando G. S. L. Brandao
We prove that any one-dimensional (1D) quantum state with small quantum conditional mutual information in all certain tripartite splits of the system, which we call a quantum appro…
Information-theoretical analysis of topological entanglement entropy and multipartite correlations
Kohtaro Kato, Fabian Furrer, Mio murao
A special feature of the ground state in a topologically ordered phase is the existence of large scale correlations depending only on the topology of the regions. These correlation…
Information-theoretical formulation of anyonic entanglement
Kohtaro Kato, Fabian Furrer, Mio Murao
Anyonic systems are modeled by topologically protected Hilbert spaces which obey complex superselection rules restricting possible operations. These Hilbert spaces cannot be decomp…