Topological superconductivity in hourglass Dirac chain metals (Ti, Hf)IrGe

Fuente: arXiv
Salvato in:
Dettagli Bibliografici
Autori principali: Meena, Pavan Kumar, Samanta, Dibyendu, Jangid, Sonika, Kushwaha, Roshan Kumar, Stewart, Rhea, Hillier, Adrian D., Ghosh, Sudeep Kumar, Singh, Ravi Prakash
Natura: Preprint
Pubblicazione: 2025
Soggetti:
Accesso online:
Tags: Aggiungi Tag
Nessun Tag, puoi essere il primo ad aggiungerne!!
_version_ 1866913696865845248
author Meena, Pavan Kumar
Samanta, Dibyendu
Jangid, Sonika
Kushwaha, Roshan Kumar
Stewart, Rhea
Hillier, Adrian D.
Ghosh, Sudeep Kumar
Singh, Ravi Prakash
author_facet Meena, Pavan Kumar
Samanta, Dibyendu
Jangid, Sonika
Kushwaha, Roshan Kumar
Stewart, Rhea
Hillier, Adrian D.
Ghosh, Sudeep Kumar
Singh, Ravi Prakash
contents Realizing topological superconductivity in stoichiometric materials is a key challenge in condensed matter physics. Here, we report the discovery of ternary germanide superconductors, $M$IrGe ($M$ = Ti, Hf), as prime candidates for topological superconductivity, predicted to exhibit nonsymmorphic symmetry-protected hourglass Dirac chains. Using comprehensive thermodynamic and muon-spin rotation/relaxation ($μ$SR) measurements, we establish these materials as conventional bulk type-II superconductors with transition temperatures of 2.24(5) K for TiIrGe and 5.64(4) K for HfIrGe, featuring a full gap and preserved time-reversal symmetry. First-principles calculations reveal striking topological features in $M$IrGe, including hourglass-shaped bulk dispersions and a Dirac chain -- a ring of fourfold-degenerate Dirac points protected by nonsymmorphic symmetry. Each Dirac point corresponds to the neck of the hourglass dispersion, while the Dirac chain gives rise to drumhead-like surface states near the Fermi level. Additionally, nontrivial $\mathbb{Z}_2$ topology leads to isolated Dirac surface states with helical spin textures that disperse across the Fermi level, forming an ideal platform for proximity-induced topological superconductivity. The coexistence of conventional bulk superconductivity, symmetry-protected hourglass topology, and helical spin-textured surface states establishes $M$IrGe as a rare and robust platform to realize topological superconductivity, opening new avenues for next-generation quantum technologies.
format Preprint
id arxiv_https___arxiv_org_abs_2502_07475
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Topological superconductivity in hourglass Dirac chain metals (Ti, Hf)IrGe
Meena, Pavan Kumar
Samanta, Dibyendu
Jangid, Sonika
Kushwaha, Roshan Kumar
Stewart, Rhea
Hillier, Adrian D.
Ghosh, Sudeep Kumar
Singh, Ravi Prakash
Superconductivity
Realizing topological superconductivity in stoichiometric materials is a key challenge in condensed matter physics. Here, we report the discovery of ternary germanide superconductors, $M$IrGe ($M$ = Ti, Hf), as prime candidates for topological superconductivity, predicted to exhibit nonsymmorphic symmetry-protected hourglass Dirac chains. Using comprehensive thermodynamic and muon-spin rotation/relaxation ($μ$SR) measurements, we establish these materials as conventional bulk type-II superconductors with transition temperatures of 2.24(5) K for TiIrGe and 5.64(4) K for HfIrGe, featuring a full gap and preserved time-reversal symmetry. First-principles calculations reveal striking topological features in $M$IrGe, including hourglass-shaped bulk dispersions and a Dirac chain -- a ring of fourfold-degenerate Dirac points protected by nonsymmorphic symmetry. Each Dirac point corresponds to the neck of the hourglass dispersion, while the Dirac chain gives rise to drumhead-like surface states near the Fermi level. Additionally, nontrivial $\mathbb{Z}_2$ topology leads to isolated Dirac surface states with helical spin textures that disperse across the Fermi level, forming an ideal platform for proximity-induced topological superconductivity. The coexistence of conventional bulk superconductivity, symmetry-protected hourglass topology, and helical spin-textured surface states establishes $M$IrGe as a rare and robust platform to realize topological superconductivity, opening new avenues for next-generation quantum technologies.
title Topological superconductivity in hourglass Dirac chain metals (Ti, Hf)IrGe
topic Superconductivity
url https://arxiv.org/abs/2502.07475