Long-lifetime spin excitations near domain walls in 1T-TaS2

Anuva Aishwarya, Arjun Raghavan, Sean Howard, Zhuozhen Cai, Gohil S. Thakur, Choongjae Won, Sang Wook Cheong, Claudia Felser, Vidya Madhavan

Research output: Contribution to journalArticlepeer-review


Spin chains in solid state materials are quintessential quantum systems with potential applications in spin-based logic, memory, quantum communication, and computation. A critical challenge is the experimental determination of spin lifetimes with the ultimate goal of increasing it. Local measurements by scanning tunneling microscopy (STM) have demonstrated the importance of decoupling spins from their environment, with markedly improved lifetimes in spin chains on the surfaces of band insulators. In this work we use low-temperature scanning tunneling microscopy to reveal long-lifetime excitations in a chain of spin-1/2 electrons embedded in a charge density wave Mott insulator, 1T-TaS2. Naturally occurring domain walls trap chains of localized spin-1/2 electrons in nearby sites, whose energies lie inside the Mott gap. Spin-polarized measurements on these sites show distinct two-level switching noise, as well as negative differential resistance in the dI/dV spectra, typically associated with spin fluctuations. The excitations show exceptionally long lifetimes of a few seconds at 300 mK. Our work suggests that layered Mott insulators in the chalcogenide family, which are amenable to exfoliation and lithography, may provide a viable platform for quantum applications.

Original languageEnglish (US)
Article numbere2121740119
JournalProceedings of the National Academy of Sciences of the United States of America
Issue number22
StatePublished - May 31 2022


  • noise spectroscopy
  • scanning tunneling microscopy
  • spin chain

ASJC Scopus subject areas

  • General


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