CEQM Seminar

Abstract: At the heart of the Weyl semimetal are massless, chiral quasiparticles that derive from electronic band-crossings split by either spatial inversion or time-reversal symmetry breaking. The resulting nodal points in the bulk band structure serve as sources and sinks of “topological charge” that are responsible for the phenomenology usually associated with these materials, including open Fermi arc surface states and the chiral anomaly.

Abstract: Strongly correlated and topological phases in condensed matter systems are at the cutting edge of fundamental physics studies, as well as being promising candidates for the next generation of technological capabilities like quantum computing. In recent years, a remarkable amount of progress has been made in creating and controlling such phases by introducing a small twist angle or lattice mismatch between two-dimensional (2D) materials.

Abstract: The development of pulsed Electron Spin Resonance (ESR) spectroscopy at microwave frequencies above 100 GHz remains a challenging and costly task, primarily due to the limited output power of modern high-frequency solid-state electronics. Nonetheless, a range of critical scientific problems—such as dynamic nuclear polarization (DNP) enhancement of NMR and quantum computing applications involving electron spins—necessitate spin relaxation measurements at THz frequencies.

Quantum phononics is an important field of research because it deals with the study of phonons (quanta of vibrational energy in materials) in the context of quantum mechanics. Since the idea of phonons possessing pseudo-angular momentum was proposed a decade ago, chiral phonons have been studied for their potential in the development of new quantum information technologies. Multiple chiral phonon responses by helicity-resolved (HR)Raman have been demonstrated.

Lunch begins at noon

Resistive switching and spintronics emerged among the leading approaches for the development of scalable and energy-efficient memories and information processing devices. In resistive switching systems, an electrical stimulus, voltage or current, programs the material’s resistivity. In spintronics, electrical signals are used to manipulate and probe the material’s magnetic configuration.

Abstract: There are two fundamentally different ways to carry out a time resolved inelastic light scattering experiment: Firstly, one can drive elementary excitations and form new photonic states of matter not intrinsic to the ground state of the investigated material. Secondly, we can quench the free energy “Mexican-Hat Potential” of order in condensed matter leading to the population of the lowest-energy stable excitation characteristic for the ordered state.