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

Anuva’s Thesis Defense

Congratulations to Anuva on successfully defending her PhD Thesis, Exploring the Strongly Correlated Realm of Electrons Using Scanning Tunneling Spectroscopy!

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!

Latest Research Highlights

Charge-Density-Waves Sensitive to Magnetic Fields in UTe2

<center>Magnetic Field Dependent Charge-Density-Waves in UTe2</center>
Magnetic Field Dependent Charge-Density-Waves in UTe2

Nature 618, 918-923 (2023)

We have found evidence for an unusual charge-density-wave order in the heavy-fermion, spin-triplet superconductor UTe2. This interesting CDW is incommensurate and weakens in intensity with increasing magnetic field. In collaboration with theorists, we have constructed a Ginzburg-Landau model for a uniform spin-triplet superconductor which coexists with three triplet pair-density-wave states. Our theory then gives rise to daughter CDWs which would be sensitive to magnetic field due to their origins in pair-density-wave states. Our paper is published along with 3 other reports of pair-density waves measured by STM, as described in this Nature News & Views article.

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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