TY  - JOUR
AU  - Reich, Adrian
AU  - Shapiro, Dmitrii
AU  - Shnirman, Alexander
TI  - Berezinskii-Kosterlitz-Thouless transitions in a topological superconductor-ferromagnet-superconductor junction
JO  - Physical review / B
VL  - 111
IS  - 20
SN  - 2469-9950
CY  - Woodbury, NY
PB  - Inst.
M1  - FZJ-2025-02801
SP  - 205428
PY  - 2025
AB  - We investigate quantum phase transitions in a topological Josephson junction with an embedded ferromagnetic layer, revealing a rich landscape of critical phenomena. The low-energy excitations comprise Majorana fermions propagating along the junction, coupled to the magnons in the ferromagnet. Based on mean-field and renormalization group arguments, we predict Berezinskii-Kosterlitz-Thouless (BKT) transitions in this system, both in the case of a magnetic easy-plane and weak easy-axis anisotropy. In the latter case, this is based on an emergent effective easy plane, spanned by the easy axis and the component of the magnetization, which couples to the Majoranas. We conclude by presenting a conjecture for the full phase diagram of the model. It covers BKT transitions as well as exotic multicritical and supersymmetric points known from related models of interacting real fermions and bosons.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:001501238000004
DO  - DOI:10.1103/PhysRevB.111.205428
UR  - https://juser.fz-juelich.de/record/1043251
ER  -