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Caltech

Physics Colloquium

Thursday, May 23, 2024
4:00pm to 5:00pm
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Online and In-Person Event
Searching for topological superconductors using ultrasound
Brad Ramshaw, Cornell University,

"For more than a century, superconductors have been the paradigmatic "quantum material", providing fundamental discoveries like gauge symmetry breaking and impacting technologies from medical imaging to quantum computing. Despite their central importance, characterizing new types of superconductors is still a difficult task: all superconductors have zero resistance, but their more subtle properties related to entanglement and topology are hard to probe experimentally. I will introduce chiral topological superconductors in two dimensions - a type of superconductivity with a "knot" in the superconducting wave function. These superconductors can host Majorana edge modes and bound states in their vortex cores, but finding a real-life example has proven challenging. I will show how we use ultrasound - deforming a crystalline lattice in a manner not unlike how gravity waves deform spacetime - to test whether a particular superconductor has the "right ingredients" to be a 2D topological superconductor. I will present the progress we have made thus far - ruling out many proposed candidate materials and discovering an unexpected new type of superconductivity along the way - and give a prognosis for what I think the most promising route is for discovering a 2D topological superconductor."

Join via Zoom:
https://caltech.zoom.us/j/81866929019
Meeting ID: 818 6692 9019

The colloquium is held in Feynman Lecture Hall, 201 E. Bridge.

For more information, please contact Denise Lu by email at [email protected].