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

Jorge’s Thesis Defense

Congratulations to Jorge on successfully defending his PhD Thesis, Stress and Crystal Imperfections: Tools for the Exploration of Unconventional Superconductivity via Scanning Tunneling Microscopy!

Anuva Wins Wayne B. Nottingham Prize!

Anuva has won the Wayne B. Nottingham Prize at the 2022 Physical Electronics Conference in Chicago; congratulations, Anuva!

APS Talks and Awards 2022

Congratulations to Seokjin, Anuva, Rachel, and Arjun on presenting talks at the 2022 American Physical Society March Meeting! Also, congratulations to Arjun on receiving a Scott Anderson Outstanding 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 Highlights

Spin-Selective Tunneling from a Nanowire STM Tip

<center>Spin-Selective Tunneling from SmB6 Nanowires</center>
Spin-Selective Tunneling from SmB6 Nanowires

Science 377, 1218-1222 (2022)

Since the discovery of topological insulators (TIs), a variety of applications have been proposed. One of the important characteristics which TIs exhibit is spin-momentum locking, in which the spin of an electron depends on the direction in which it is traveling. By fabricating nanowire tips with the putative Kondo TI SmB6, we have been able to observe spin-polarized tunneling with a non-magnetic tip on to the surface of the antiferromagnet FeTe. This novel technique will help pave the way for a number of cutting-edge applications with topological insulators.

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.

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