activity
20242026
collaborators

7 papers

cond-mat.str-el2026

Repulsive-Interaction-Driven Topological Superconductivity in a Landau Level Coupled to an -Wave Superconductor

Koji Kudo, Ryota Nakai, Hiroki Isobe +2

A two-dimensional topologically nontrivial state of noninteracting electrons, such as the surface state of a three-dimensional topological insulator, is predicted to realize a topo…

cond-mat.mes-hall2026

Phase-shift instanton approach to tunneling duality in Read--Rezayi state

Ryoi Ohashi, Hiroki Isobe, Ryota Nakai +1

We study the duality between quasi-particle and electron tunneling in point-contact geometries of fractional quantum Hall states. To treat non-Abelian edge operators, we introduce…

cond-mat.mes-hall2026

Topological superconductivity on a kagome magnet coupled to a Rashba superconductor

Koji Kudo, Ryota Nakai, Hiroki Isobe +1

A quantum anomalous Hall system is predicted to realize topological superconductivity when proximity-coupled to an -wave superconductor. A kagome magnet with chiral magnetic ord…

cond-mat.mes-hall2025

Chirality-selective proximity effect between chiral -wave superconductors and quantum Hall insulators

Ryota Nakai, Koji Kudo, Hiroki Isobe +1

Heterostructures of superconductors and quantum-Hall insulators are promising platforms of topological quantum computation. However, these two systems are incompatible in some aspe…

cond-mat.stat-mech2025

Discrete time crystals detected by time-translation twist

Ryota Nakai, Taozhi Guo, Shinsei Ryu

We introduce a boundary condition twisted by time translation as a novel probe to characterize dynamical phases in periodically driven (Floquet) quantum systems. Inspired by twiste…

cond-mat.str-el2024

Quantum anomalous, spin, and valley Hall effects in pentalayer rhombohedral graphene moiré superlattices

Koji Kudo, Ryota Nakai, Kentaro Nomura

Recent experiments on pentalayer rhombohedral graphene moiré superlattices have observed the quantum anomalous Hall effect at moiré filling factor of and various fraction…