71 citations · 281 across the 29 of their papers we have counts for
30 papers
Jordan-Wigner mapping between quantum-spin and fermionic Casimir effects
Katsumasa Nakayama, Kei Suzuki
The Jordan-Wigner transformation connects spin operators in one-dimensional spin systems and fermionic operators. In this work, we elucidate the relationship between the finite-siz…
Anomalous-magnetic-moment-enhanced Casimir effect
Daisuke Fujii, Katsumasa Nakayama, Kei Suzuki
We theoretically investigate the impact of the anomalous magnetic moment (AMM) of Dirac fermions on the fermionic Casimir effect under magnetic fields. We formulate it as an extens…
Casimir effect in magnetic dual chiral density waves
Daisuke Fujii, Katsumasa Nakayama, Kei Suzuki
We theoretically investigate the Casimir effect originating from Dirac fields in finite-density matter under a magnetic field. In particular, we focus on quark fields in the magnet…
Lifshitz formulas for finite-density Casimir effect
Daisuke Fujii, Katsumasa Nakayama, Kei Suzuki
The Lifshitz formula is well known as a theoretical approach to investigate the Casimir effect at finite temperature. In this Letter, we generalize the Lifshitz formula to the Casi…
Initial tensor construction and dependence of the tensor renormalization group on initial tensors
Katsumasa Nakayama, Manuel Schneider
We propose a method to construct a tensor network representation of partition functions without singular value decompositions nor series expansions. The approach is demonstrated fo…
Dual chiral density wave induced oscillating Casimir effect
Daisuke Fujii, Katsumasa Nakayama, Kei Suzuki
The Casimir effect is known to be induced from photon fields confined by a small volume, and also its fermionic counterpart has been predicted in a wide range of quantum systems. H…
Casimir effect in axion electrodynamics with lattice regularizations
Katsumasa Nakayama, Kei Suzuki
The Casimir effect is induced by the interplay between photon fields and boundary conditions, and in particular, photon fields modified in axion electrodynamics may lead to the sig…
Randomized higher-order tensor renormalization group
Katsumasa Nakayama
The higher-order tensor renormalization group (HOTRG) is a fundamental method to calculate the physical quantities by using a tensor network representation. This method is based on…
Chiral fermion in the Hamiltonian lattice gauge theory
Tomoya Hayata, Katsumasa Nakayama, Arata Yamamoto
We discuss the chiral fermion in the Hamiltonian formalism of lattice gauge theory. Although the naive chiral charge operator does not commute with the Hamiltonian, the commutable…
Casimir effect for fermions on the lattice
Katsumasa Nakayama, Kei Suzuki
The conventional Casimir effect has been studied in the continuous spacetime, but to elucidate its counterpart in the lattice space is an important subject. Here, we discuss variou…
Dirac/Weyl-node-induced oscillating Casimir effect
Katsumasa Nakayama, Kei Suzuki
The Casimir effect is a quantum phenomenon induced by the zero-point energy of relativistic fields confined in a finite-size system. This effect for photon fields has been studied…
Remnants of the nonrelativistic Casimir effect on the lattice
Katsumasa Nakayama, Kei Suzuki
The Casimir effect is a fundamental quantum phenomenon induced by the zero-point energy for a quantum field. It is well-known for relativistic fields with a linear dispersion relat…
Phase structure of the CP(1) model in the presence of a topological -term
Katsumasa Nakayama, Lena Funcke, Karl Jansen +2
We numerically study the phase structure of the CP(1) model in the presence of a topological -term, a regime afflicted by the sign problem for conventional lattice Monte Carlo s…
Kondo effect with Wilson fermions
Tsutomu Ishikawa, Katsumasa Nakayama, Kei Suzuki
We investigate the Kondo effect with Wilson fermions. This is based on a mean-field approach for the chiral Gross-Neveu model including four-point interactions between a light Wils…
Lattice-fermionic Casimir effect and topological insulators
Tsutomu Ishikawa, Katsumasa Nakayama, Kei Suzuki
The Casimir effect arises from the zero-point energy of particles in momentum space deformed by the existence of two parallel plates. For degrees of freedom on the lattice, its ene…
Casimir effect for lattice fermions
Tsutomu Ishikawa, Katsumasa Nakayama, Kei Suzuki
We propose a definition of the Casimir energy for free lattice fermions. From this definition, we study the Casimir effects for the massless or massive naive fermion, Wilson fermio…
Charmonium contribution to $B \rightarrow K\ell^+\ell^-: testing the factorization approximation on the lattice
Katsumasa Nakayama, Tsutomu Ishikawa, Shoji Hashimoto
We report the current status of a study of charmonium contribution to on the lattice. Our lattice calculation tests the factorization approximation fo…
Renormalization of bilinear and four-fermion operators through temporal moments
Tsutomu Ishikawa, Katsumasa Nakayama, Shoji Hashimoto
We propose a renormalization scheme that can be simply implemented on the lattice. It consists of the temporal moments of two-point and three-point functions calculated with finite…
A lattice formulation of the Atiyah-Patodi-Singer index
Hidenori Fukaya, Naoki Kawai, Yoshiyuki Matsuki +4
Atiyah-Singer index theorem on a lattice without boundary is well understood owing to the seminal work by Hasenfratz et al. But its extension to the system with boundary (the so-ca…
Renormalization group on a triad network
Daisuke Kadoh, Katsumasa Nakayama
We propose a new renormalization scheme of tensor networks made only of third order tensors. The isometry used for coarse-graining the network can be prepared at an comput…
mesons as a probe of Casimir effect for chiral symmetry breaking
Tsutomu Ishikawa, Katsumasa Nakayama, Daiki Suenaga +1
We propose mesons as probes to investigate finite-volume effects for chiral symmetry breaking at zero and finite temperature. By using the -flavor linear-sigma model with…
Test of factorization for the long-distance effects from charmonium on
Katsumasa Nakayama, Shoji Hashimoto
We report on a calculation of the charmonium contribution to the decay using lattice simulations with 2+1 flavors of Mobius domain wall fermions. We f…
Lattice study of supersymmetry breaking in N=2 supersymmetric quantum mechanics
Daisuke Kadoh, Katsumasa Nakayama
We study supersymmetry breaking from a lattice model of N=2 supersymmetric quantum mechanics using the direct computational method proposed in arXiv:1803.07960. The vanishing Witte…
Casimir effect for nucleon parity doublets
Tsutomu Ishikawa, Katsumasa Nakayama, Kei Suzuki
Finite-volume effects for the nucleon chiral partners are studied within the framework of the parity-doublet model. Our model includes the vacuum energy shift for nucleons, which i…