activity
20242026
collaborators

6 papers

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

Universal Transport Theory for Paired Fractional Quantum Hall States in the Quantum Point Contact Geometry

Eslam Ahmed, Ryoi Ohashi, Hiroki Isobe +2

Even-denominator fractional quantum Hall (FQH) states can be viewed as topological superconductors of composite fermions, supporting a charged chiral mode and

cond-mat.supr-con2026

Magnetic penetration depth in topological superconductors: Effect of Majorana surface states and application for UTe

Kazuki Akuzawa, Jushin Tei, Ryoi Ohashi +2

In this study, we examine how orbital degrees of freedom and Majorana surface states influence the magnetic penetration depth in the superconductor UTe. Using a two-orbital mod…

cond-mat.supr-con2025

Detecting Topological Phase Transition in Superconductor-Semiconductor Hybrids by Electronic Raman Spectroscopy

Takeshi Mizushima, Yukio Tanaka, Jorge Cayao

In superconductor-semiconductor hybrids, applying a magnetic field closes a trivial bulk gap and causes a topological phase transition (TPT), resulting in the emergence of Majorana…

cond-mat.supr-con2025

Collective modes in Fulde-Ferrell-Larkin-Ovchinnikov superconductors: The role of long-range Coulomb interaction and signatures in density response

Ryoga Miwa, Ryoi Ohashi, Satoshi Fujimoto +1

We theoretically investigate collective excitations in the Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) states of Pauli-limited superconducting films. When the long-range Coulomb intera…

cond-mat.supr-con2024

Anisotropic paramagnetic response of topological Majorana surface states in the superconductor

Ryoi Ohashi, Jushin Tei, Yukio Tanaka +2

Identifying the superconducting gap symmetry and topological signatures in the putative spin-triplet superconductor is an important issue. Especially, a smoking-gun…