activity
20242026
collaborators

19 papers

cond-mat.str-el2026

Floquet-Weyl states at one-photon resonances in three-dimensional topological insulators

Keiya Uehara, Ryo Okugawa, Takami Tohyama +1

Quantum materials exhibit exotic phases and electronic responses under irradiation by circularly polarized light, which breaks time-reversal symmetry and generates Floquet replica…

cond-mat.mtrl-sci2026

Thermoelectric and Magnetic Properties in Doped FeVAl within a Bipolar Random Anderson Model

Takami Tohyama, Hidetoshi Fukuyama

We investigate the thermoelectric and magnetic properties of Si-substituted -type and Ti-substituted -type Heusler alloy FeVAl using the bipolar random Anderson model, wh…

cond-mat.mes-hall2026

Quasiperiodicity-induced non-Hermitian skin effect from the breakdown of scale-free localization

Kazuma Saito, Ryo Okugawa, Kazuki Yokomizo +2

Non-reciprocal systems exhibit extreme sensitivity to boundary conditions, typically manifesting as the non-Hermitian skin effect (NHSE) under open boundaries. By bridging the boun…

cond-mat.supr-con2026

Quantum-geometric origin of superfluid weight in quasicrystals with critical states

Kazuma Saito, Ryo Okugawa, Yusuke Kato +1

A distinctive feature of many quasiperiodic systems is the presence of critical states that are neither extended nor exponentially localized. We investigate the geometric effect on…

cond-mat.supr-con2026

BCS-BEC crossover driven by small Fermi pockets of a high-Tc cuprate superconductor

Junhyeok Jeong, Yamato Enomoto, Yoshimitsu Kohama +16

Fermi arcs observed in underdoped cuprates have sparked debate over whether they represent segments of a large Fermi surface or small Fermi pockets. This ambiguity has long hindere…

cond-mat.str-el2026

The antiferromagnetic Chern insulator phase in the Kane-Mele-Hubbard model

Bao-Qing Wang, Can Shao, Takami Tohyama +2

The emergence of the antiferromagnetic (AFM) Chern insulator (AFCI) phase in the Kane-Mele-Hubbard (KMH) model with a finite sublattice potential is investigated. The AFCI, charact…