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Caltech

IQIM Postdoctoral and Graduate Student Seminar

Wednesday, April 17, 2024
12:00pm to 1:00pm
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East Bridge 114
Non-reciprocity in quantum materials
Philip Moll, Max-Planck Institute,

Abstract: Diodes are indispensable elements of electronics and logic processing that are mainly realized technologically in semiconductor heterostructures. The strong internal gradients of p-n junctions break all symmetries relating forward to backward flow and hence define a forward direction. Currently ideas are brought forward to achieve non-reciprocity in homogeneous conductors, relying on internal symmetry breaking in more exotic materials. I will touch on two main streams of ideas, the first evolving around non-reciprocity in superconductors known as the superconducting diode effect. Operated at cryogenic temperatures, this effect promises ideal rectification building on versatile superconducting design strategies. While commonly achieved in non-centrosymmetic materials or heterostructures, recently strong diode effects have appeared in homogeneous conventional superconductors by utilizing their 3D mesoscopic shape. A second route involves current rectification in spin-orbit coupled materials under strong magnetic fields. Here, the degree of symmetry breaking can be externally tuned, and so is the diode direction and efficiency. Focusing on the Kagome conductor CsV3Sb5, field-switchable diodes are demonstrated as a new class of non-structural diode.

Lunch will be provided, following the talk, on the lawn north of the Bridge Building.

For more information, please contact Marcia Brown by phone at 626-395-4013 or by email at [email protected].