Odd-parity ground state in dilute Yu-Shiba-Rusinov dimers and chains

• DOI: 10.1103/physrevb.111.205424
• Publication Date: 2025-05-20T14:52:12Z
• Authors: Lisa M. Rütten; Harald Schmid; Werner M. J. van ...; Eva Liebhaber; Kai Rossnagel; Katharina J. Franke
• Keywords: Parity (physics)

Magnetic adatoms on superconductors induce Yu-Shiba-Rusinov (YSR) states, which are key to the design of low-dimensional correlated systems and topological superconductivity. Competing magnetic interactions superconducting pairing lead a rich phase diagram. Using scanning tunneling microscope (STM), we position Fe atoms <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"><a:mrow><a:mn>2</a:mn><a:mi>H</a:mi><a:mtext>−</a:mtext><a:msub><a:mi>NbSe</a:mi><a:mn>2</a:mn></a:msub></a:mrow></a:math> build dimer with an odd-parity ground state, i.e., partially screened YSR channel hybridized states spanning Fermi level. This state makes promising precursor for chain. By adding one atom at time, track formation bands. The lowest-energy band crosses level, find strong site-dependent spectral variations especially chain's terminations. We attribute these features quantum spin effects ferromagnetic coupling influenced by local chemical environment. Published American Physical Society 2025