ECE Seminar: Dr. Jian Shi "Switchable Spin-Momentum Relations in Dresselhaus Semiconductors"

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Abstract: Quantum well structures lacking inversion symmetry host a plethora of exciting physical phenomena. In this talk, we show the design, creation, and electron-spin-lattice interactions of quantum well polar materials for spintronics and energy transduction. First, we show the role of dimensionality on the phonon and polarization dynamics of free-standing two-dimensional membranes. Then, we show the discovery of the persistent spin helix in a hybrid ferroelectric perovskite with a natural quantum well structure. We demonstrate that the spin-polarized band structure is switchable at room temperature via an intrinsic ferroelectric field. The favored short spin helix wavelength (three orders of magnitude shorter than in III–V materials), room-temperature operation and non-volatility make the hybrid perovskite an ideal platform for understanding symmetry-tuned spin dynamics, towards designing spintronic or spin-orbit qubit materials and devices that can resolve the control-dephasing dilemma.

Bio: Dr. Jian Shi is a Professor in the Department of Materials Science and Engineering, and Department of Physics at Rensselaer Polytechnic Institute. Dr. Shi is currently also a Simons Foundation Pivot Fellow at the University of Chicago. Dr. Shi was a postdoctoral research fellow at Harvard University from 2013 to 2014. Dr. Shi received his Ph.D. degree in Materials Science at the University of Wisconsin at Madison in 2012. He is a recipient of the AFSOR Young Investigator program award in 2018, a recipient of IEEE Ferroelectrics Young Investigator Award in 2023, and a recipient of the Simons Foundation Pivot Fellowship in 2023. He is also an associate editor of Journal of Applied Physics. As an experimenter, Jian Shi’s current research foci are: polar, spintronic, chiral, Berry parameters-tunable, and superconducting materials for computing and energy.