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!

Vidya Elected to American Academy of Arts & Sciences

Congratulations to Vidya on being elected to the prestigious American Academy of Arts and Sciences for 2023! Vidya is joined by Prof. David Cahill and Prof. Tamer Basar as inductees from the University of Illinois Urbana-Champaign this year!

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!


Latest Research Highlights


Optical Manipulation of Charge Order in RbV3Sb5 Visualized by Laser STM

<center>Optical Manipulation of Charge Order in RbV3Sb5</center>
Optical Manipulation of Charge Order in RbV3Sb5

Nature 631, 60-66 (2024)

We have discovered a novel technique to optically manipulate charge order in the kagome superconductor RbV3Sb5. Using our unique laser-coupled STM set-up, we apply linearly polarized light along high-symmetry directions and find that the relative intensities of CDW peaks can be reversibly switched. We also find that the CDW order can be manipulated by perpendicular magnetic fields. In collaboration with theorists, we show that the simplest CDW matching our data is an out-of-phase combination of vanadium bond order and orbital loop currents. Our laser STM technique opens doors toward dynamical optical control of complex quantum phenomena in quantum materials.


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.




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