Physics & Astronomy Colloquium: Prof. Christos Panagopoulos, NTU Singapore

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Location: 127 Nieuwland Science Hall (View on map )

Engineering Spin Topology for Quantum Functionality

Prof. Christos Panagopoulos
Nanyang Technological University, Singapore

The electric field experienced by a traveling electron translates, in its rest frame, to a magnetic field proportional to its velocity. The ZeemanĀ  interaction between the electron spin and this effective magnetic field is equivalent to the coupling of the electron spin and momentum degrees of freedom, known as spin-orbit coupling (SOC). Importantly, SOC effects are greatly enhanced in reduced dimensions: inversion symmetry is broken at a surface or interface, and the resultant electric field couples to the spin of itinerant electrons. In magnetic materials, for example, the states induced by engineering SOC and inversion symmetry-breaking open a broad perspective with an impact on the technology of spin topology [1-3]. Using novel materials platforms that we developed recently [4, 5], I will discuss quantifiable insights toward the stability and dynamics of tailored spin textures and demonstrate the viability of spin topology to influence a superconductor at selective length scales for adaptable recipes for fluxonics and chiral superconductivity. Time permitting, I will also talk about complementary spin configurations that develop quantized helicity excitations, offering a new class of building blocks for realizing quantum logic elements [6].

[1] A. Soumyanarayanan, N. Reyren, A. Fert and C. Panagopoulos, Nature 539, 507 (2016).
[2] A. Bogdanov and C. Panagopoulos, Physics Today 73(3), 44 (2020).
[3] A. Bogdanov and C. Panagopoulos, Nature Reviews Physics 2, 492 (2020).
[4] A. Soumyanarayanan, M. Raju, A. Oyarce, A. Tan, M. Im, A. Petrovic, P. Ho, M. Tran, C. Gan, F. Ernult and C. Panagopoulos, Nature Materials 16, 898 (2017).
[5] A. Petrovic, M. Raju, X. Tee, A. Louat, I. Aprile, R. Menezes, M. Wysznski, M. Reznikov, C. Renner, M. Milosevic and C. Panagopoulos, Phys. Rev. Lett. 126, 117205 (2021).
[6] C. Psaroudaki and C. Panagopoulos, Phys. Rev. Lett. 127, 067201 (2021).

Hosted by Prof. Forro