Mesoscale and Nanoscale Physics
We argue that the static dielectric constant of small (thin and/or narrow) semiconductor and insulator nanostructures depends strongly on the their environment. We do so by considering the electronic response simply reviewing, briefly but…
Bulk-Rashba spin splitting is forbidden in tetradymite topological insulators like Bi$_2$Se$_3$ or Bi$_2$Te$_3$, since their quintuple-layer stacking preserves inversion symmetry. We show that BiSbTeSe$_2$ escapes this restriction: in the…
Reducing the electrical current required to excite magnetization dynamics is a central challenge, e.g. for energy-efficient magnonic devices or oscillator-based computing. Spin Hall oscillators typically rely on large current densities to…
We study the quantum transport of massless Dirac fermions through two asymptotically flat graphene sheets connected by a structurally asymmetric catenoid wormhole in $(2+1)$-dimensional curved spacetime. Analytic scattering basis functions…
The dynamics of a nuclear spin bath generates magnetic noise that is a key contributor to the decoherence of electron spin qubits in electrostatically-defined quantum dots. In this paper, we extend the cluster correlation expansion (CCE)…
Van der Waals (vdW) based antiferromagnets (AFMs) are an ideal platform for probing and understanding thickness- and twist-angle-dependent emergent spin phenomena. However, element-specific nanoscale characterization of the spin structure…
Accumulated disorder at physical boundaries prevents the realization of ideal zero-dissipation topological edge channels. Here, we propose a strain engineering mechanism to create a topological domain wall in the pristine material bulk,…
Quantum oscillations offer a direct probe of Fermi-surface topology and electronic degeneracy, yet disentangling both simultaneously across the Lifshitz transitions of multiband systems has remained an open experimental challenge. Here, we…
The nonlinear transport properties of solids are deeply rooted in the quantum geometry of their electronic wavefunctions, which is encoded in the quantum geometric tensor. Its real part, known as the quantum metric, has been recently…
Proximity effects in layered heterostructures are usually represented by static parameters fitted to first-principles bands, which discards the energy dependence of the virtual hybridization, the momentum transfer, and the spatial…
Global diagnostics such as Berry curvature and quantum metrics characterize the geometry and topology of an occupied Bloch subspace, leaving the microscopic sectors that carry this structure implicit. We introduce the relative hybridization…
Clean, nonsplit vortex zero-bias peaks (ZBPs) can be misinterpreted as Majorana zero modes (MZMs), making static scanning tunneling microscopy intrinsically ambiguous. Here we use the STM tip coupling to drive a local…
Colloidal semiconductor quantum dots are promising materials for numerous applications due to their tunable emission and high quantum yields. However, emission instability in the form of luminescence blinking remains a significant obstacle…
The asymmetric expansion of magnetic bubble domains in ultrathin ferromagnets provides a powerful route to probe the interfacial Dzyaloshinskii-Moriya interaction (DMI). While conventional analyses rely on domain wall velocities measured…
This thesis investigates how superperiodicity, quasiperiodicity, and disorder shape electronic and spin transport in graphene-based systems, with an emphasis on experimentally relevant length scales and realistic atomistic modeling. Using…
Twisted graphene layers host van Hove singularities (vHSs), peaks in the electronic density of states, thought to drive exotic phases in moir\'e materials, but their effect on thermal transport has remained unclear. Here we show that vHSs…
Entanglement carries universal content that labels phases and critical points. We study the entanglement entropy of the steady states of critical non-Hermitian free-fermion chains. It scales logarithmically with subsystem size, but the…
Spin, pseudospin, valley, polarization, and other two-component degrees of freedom share the geometry of SU(2), yet their topological manifestations are usually discussed as separate phenomena. This review develops a common geometric…
Photoexcited charge carriers in topological insulators display anomalously long-range transport at cryogenic temperatures, but the underlying mechanism remains under debate. Here we use a transverse electric field as a discriminating probe…
Unstrained bulk germanium is a particularly attractive material for circuit quantum electrodynamics with spins (spin-cQED). We show, through systematic modeling and comparison with state-of-the-art strained germanium heterostructures, that…