11 citations · 26 across the 15 of their papers we have counts for
18 papers
Realizing Braided Fusion 2-Categories as (3+1)D Mixed-State Topological Orders
Ryohei Kobayashi, Abhinav Prem, Matthew Yu
We construct large families of mixed-state topological orders in (3+1)D, including intrinsically mixed-state topological orders. We realize these theories by relating the data para…
Sipser-Spielman meets Dijkgraaf-Witten: non-Abelian qLDPC codes via twisted sheaf gauge theory and almost-constant-overhead magic state fountain
Guanyu Zhu, Shi Jie Samuel Tan, Ryohei Kobayashi +1
Sipser-Spielman codes and Dijkgraaf-Witten twisted gauge theories are among the most profound ideas in the last few decades in the areas of computer science and mathematical physic…
Fermionic Anomalies of Finite Symmetries on Lattices
Ameya Chavda, Ryohei Kobayashi
We develop a lattice characterization of fermionic 't Hooft anomalies of finite internal symmetries in one and two spatial dimensions, formulated in terms of obstructions to symmet…
Sixteen-Fold Way for Fermionic Topological Orders
Ryohei Kobayashi, Abhinav Prem, Matthew Yu
Fermionic topological orders can host 't Hooft anomalies with no bosonic counterpart. We identify a new sixteen-fold family of (2+1)D fermionic topological orders, forming a fermio…
Non-Abelian qLDPC: TQFT Formalism, Addressable Gauging Measurement and Application to Magic State Fountain on 2D Product Codes
Guanyu Zhu, Ryohei Kobayashi, Po-Shen Hsin
A fundamental problem of fault-tolerant quantum computation with quantum low-density parity-check (qLDPC) codes is the tradeoff between connectivity and universality. It is widely…
Pauli stabilizer formalism for topological quantum field theories and generalized statistics
Yitao Feng, Hanyu Xue, Ryohei Kobayashi +2
Topological quantum field theory (TQFT) provides a unifying framework for describing topological phases of matter and for constructing quantum error-correcting codes, playing a cen…
Automorphism in Gauge Theories: Higher Symmetries and Transversal Non-Clifford Logical Gates
Po-Shen Hsin, Ryohei Kobayashi
Gauge theories are important descriptions for many physical phenomena and systems in quantum computation. Automorphism of gauge group naturally gives global symmetries of gauge the…
Clifford Hierarchy Stabilizer Codes: Transversal Non-Clifford Gates and Magic
Ryohei Kobayashi, Guanyu Zhu, Po-Shen Hsin
A fundamental problem in fault-tolerant quantum computation is the tradeoff between universality and dimensionality, exemplified by the the Bravyi-König bound for -dimensional t…
Onsiteability of Higher-Form Symmetries
Yitao Feng, Yu-An Chen, Po-Shen Hsin +1
An internal symmetry in a lattice model is said to be onsiteable if it can be disentangled into an onsite action by introducing ancillas and conjugating with a finite-depth circuit…
Anyonic membranes and Pontryagin statistics
Yitao Feng, Hanyu Xue, Yuyang Li +4
Anyons, unique to two spatial dimensions, underlie extraordinary phenomena such as the fractional quantum Hall effect, but their generalization to higher dimensions has remained el…
Projective Representations, Bogomolov Multiplier, and Their Applications in Physics
Ryohei Kobayashi, Haruki Watanabe
We present a pedagogical review of projective representations of finite groups and their physical applications in quantum many-body systems. Some of our physical results are new. W…
Generalized Hall Conductivities in Local Commuting Projector Models: Generalized Symmetries and Protected Surface Modes
Po-Shen Hsin, Ryohei Kobayashi
Hall conductivities are important characterizations of phases of matter. It is known that nonzero Hall conductivities are difficult to realize in local commuting projector lattice…
Higher-Form Anomalies Imply Intrinsic Long-Range Entanglement
Po-Shen Hsin, Ryohei Kobayashi, Abhinav Prem
We show that generic gapped quantum many-body states which respect an anomalous finite higher-form symmetry have an exponentially small overlap with any short-range entangled (SRE)…
Anomalies of Coset Non-Invertible Symmetries
Po-Shen Hsin, Ryohei Kobayashi, Carolyn Zhang
Anomalies of global symmetries provide important information on the quantum dynamics. We show the dynamical constraints can be organized into three classes: genuine anomalies, frac…
Generalized Statistics on Lattices
Ryohei Kobayashi, Yuyang Li, Hanyu Xue +2
The statistics of particles and extended excitations, such as loops and membranes, are fundamental to modern condensed matter physics, high-energy physics, and quantum information…
Classifying Logical Gates in Quantum Codes via Cohomology Operations and Symmetry
Po-Shen Hsin, Ryohei Kobayashi, Guanyu Zhu
We systematically construct and classify fault-tolerant logical gates implemented by constant-depth circuits for quantum codes using cohomology operations and symmetry. These logic…
Non-Abelian Self-Correcting Quantum Memory and Transversal Non-Clifford Gate beyond the Distance Barrier
Po-Shen Hsin, Ryohei Kobayashi, Guanyu Zhu
We construct a family of infinitely many new candidate non-Abelian self-correcting topological quantum memories in spacetime dimensions without particle excitations usi…
Cross-cap defects and fault-tolerant logical gates in the surface code and the honeycomb Floquet code
Ryohei Kobayashi, Guanyu Zhu
We consider the toric code, surface code and Floquet code defined on a non-orientable surface, which can be considered as families of codes extending Shor's 9-qubit…