Condensed Matter/Materials & Biological Physics Seminar with Daniel Rhodes on Superconductivity in Noncentrosymmetric 2D Semimetals

Over the last decade, the enhancement of superconducting properties in 2D materials has been routinely observed. Typically, this enhancement is confined to the magnetic fields that 2D superconductors can withstand before the pairing of electrons is broken, known as the Pauli limit. For the more common centrosymmetric, hexagonal 2D superconductors these properties were initially expected to be isotropic and incapable of being modified without introducing considerable amounts of disorder – limiting understanding into how different ground states compete with superconductivity in the 2D limit. In this talk, I will discuss our investigations on the magnetotransport properties of an intrinsic noncentrosymmetric 2D superconductor,  few-layer 1T’-MoTe2, which has a semimetallic electronic band structure. Importantly, the semimetallic band structure enables electrostatic control over states that interact with superconductivity and understanding on how these states compete with or enhance superconductivity. The first half of this talk will focus on the unusual enhancement of the superconducting critical temperature of few-layer MoTe2, which is over a factor of seventy greater that of the bulk, while the latter will focus on the unusual dynamics between out-of-plane electric field, magnetic field orientation, and the superconductivity in bilayer MoTe2. For bilayer MoTe2 we realize, for the first time ever, a coupling between intrinsic ferroelectricity and superconductivity. In addition, we establish this material as an anisotropic superconductor with a two-fold rotational symmetry which we attribute to a special scenario referred to as, “tilted Ising spin-orbit coupling.” If time allows, I’ll talk about some of the materials challenges facing the 2D community when it comes to the exploration of materials beyond graphene and the semiconducting 2H-TMDs.

This lecture was made possible by the William C. Ferguson Fund.