STM 1 Determination of phonon modes in PbSe Reconstructed surface of KV<sub>3</sub>Sb<sub>5</sub> STM 2 The Group!

Recent News

APS Talks and Awards

Congratulations to Seokjin, Anuva, Rachel, and Arjun on presenting talks at the 2022 American Physical Society March Meeting! Also, congratulations to Arjun on receiving the Scott Anderson Graduate Assistant Award for 2022!

Guannan’s Thesis Defense

Congratulations to Guannan on completing her PhD Thesis Defense, Scanning Tunneling Microscopy and Spectroscopy Study on Layered Transition Metal Chalcogenides Thin Films Tuned by Thickness, Structural Phase, and Heterostructure!

2020 Awards

Anuva has won a PPG-MRL Fellowship for the 2020-2021 academic year; congratulations to Anuva! Guannan has won the Scott Anderson Outstanding Graduate Assistant Award for 2020 from the UIUC Dept. of Physics; congratulations, Guannan! Undergraduates Zhuozhen Cai and Will Jing have also received Summer 2020 research awards. Zhuozhen received a 2020 Lorella M. Jones Undergraduate Summer Research Award and LAS James Scholar Preble Research Fellowship; Will was awarded a Research Support Grant (RSG) sponsored by the Office of Undergraduate Research (OUR)! And, Rachel Birchmier has received a prestigious NDSEG Fellowship from the US Department of Defense for 2020! Read the Blog for more news from the Madhavan Lab.

Latest Research

Long-Lifetime Spin Excitations in a Chalcogenide Mott Insulator

<center>Long Spin Lifetimes in TaS2</center>
Long Spin Lifetimes in TaS2

Proc. Natl. Acad. Sci. USA 119, 22 (2022)

Currently, there is an intense ongoing search for 2-level quantum systems with long lifetimes, with important future applications in quantum information science and technology. While conventional platforms have focused on point defects in band insulators and semiconductors, Mott insulators provide an interesting alternative. Applying scanning tunneling microscopy and spectroscopy, we have now shown that long-lifetime spins are hosted at naturally occurring domain walls in the charge density wave Mott insulator 1T-TaS2. Our spin-polarized, atomic-scale measurements demonstrate excitation lifetimes of up to a few seconds at 300 mK. Overall, our work thus reveals chalcogenide Mott insulators, which can be easily exfoliated and manipulated with lithography techniques, as novel potential platforms for quantum information applications.

Signatures of Chiral Spin-Triplet Topological Superconductivity

<center>Chiral In-Gap States in UTe2</center>
Chiral In-Gap States in UTe2

Nature 579, 523-527 (2020)

Materials with the potential for harboring unconventional spin-triplet pairing superconductivity have attracted significant attention in the condensed matter physics community. Until now, extremely low critical temperatures and superconducting phases buried within a ferromagnetic phase or only appearing at high pressures have hampered efforts to find such materials. However, with a transition temperature of 1.6 K having been recently discovered in the heavy fermion compound UTe2, the material has presented a new opportunity to investigate possible spin-triplet pairing. Using scanning tunneling microscopy and spectroscopy, our group has found chiral in-gap states in UTe2, providing direct experimental evidence for chiral spin-triplet topological superconductivity.

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