Condensed Matter Seminar

Abstract: Superconducting devices subject to strong charging energy interactions and Coulomb blockade are one of the key elements for the development of nanoelectronics and constitute common building blocks of quantum computation platforms and topological superconducting setups. The study of their transport properties is nontrivial and some of their nonperturbative aspects are hard to capture with the most ordinary techniques. Here we present a matrix product state approach to simulate the real-time dynamics of these systems.

Abstract: Application relevant materials are usually polycrystalline, and one of the major challenges in structural analysis resides in accurately identifying the grain boundary orientation and size distribution over a wide field of view with enough spatial resolution to capture tens-of-nanometer sized domains.

Abstract: In chemistry and biochemistry, chirality represents the structural asymmetry characterized by non-superimposable mirror images for a material like DNA. In physics, however, chirality commonly refers to the spin-momentum locking of a particle or quasiparticle in the momentum space. While seemingly unrelated characters in different fields, the structural chirality leads to the electronic chirality featured by the orbital-momentum locking encoded in the wavefunction of chiral molecules or solids, i.e.

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Abstract: While the possibility of viscous electron flow in solid state systems was originally proposed as early as the 1960s [1], possible experimental realizations have remained elusive until the recent availability of several ultra-high-conductivity materials. However, distinguishing between non-Ohmic ballistic and viscous effects, and understanding their origin, has proved challenging. In the quasi-two-dimensional metal PdCoO2, the strong and unanticipated effect of Fermi surface anisotropy has added an additional layer of complexity [2].

Abstract: For centuries, we have known that when light propagates through a transparent solid, it can disperse, refract and exhibit nonlinear optical effects. However, until relatively recently, it has been more challenging to experimentally address the corresponding question: what happens to the transparent solid as light propagates through it?

Abstract: Improper phases are characterized by a secondary order parameter setting in as a direct consequence of a primary order. In this talk, we highlight an overlooked mechanism that couples order parameter bilinears to odd-parity order parameters such that the latter emerge as improper orders. To this end, we explore a novel perspective on nonsymmorphic symmetries based on extended symmetry groups in real space. We demonstrate how nonsymmorphic symmetries can generate rather nonintuitive couplings between order parameters.

Abstract: The characterisation of strongly-correlated effects in quantum impurity systems (QIS) is particularly challenging due to the infinite size of the environment and the buildup of long-ranged entanglement in the system. Moving beyond standard (perturbative) transport analysis, we develop a framework based on the Numerical Renormalisation Group (NRG) and Variational Matrix Product States (VMPS) methods to resolve strong correlations in QIS.

Abstract: Twenty years following the groundbreaking discovery of graphene, the realm of two-dimensional materials continues to amaze us with captivating physics. One exciting avenue of exploration lies in understanding how the strongly interacting electrons and topological states give rise to superconductivity. However, measuring the superfluid density of these materials is challenging because their thickness are only a few atomic layers, rendering traditional methods inadequate for this frontier of inquiry.

Abstract: For most of the last century, condensed matter physics has been dominated by the Landau's symmetry breaking theory. In this respect, by lowering the temperature, almost all forms of matter reorganize in order to generate some kind of long-range order (well known examples are given by the liquid-solid transition or the paramagnetic-ferromagnetic one). However, in the recent past, there is a clear evidence for several cases that escape this standard description and keep a disordered nature down to very low temperatures.