Thèse Unconventional Superconductivity In Vdw Heterostructures. H/F - Doctorat.Gouv.Fr

Établissement : Université Paris-Saclay GS Sciences de l'ingénierie et des systèmes École doctorale : Interfaces : matériaux, systèmes, usages Laboratoire de recherche : [UMR 8580] Laboratoire Structures, Propriétés, Modélisation des Solides Direction de la thèse : Igor KORNEV Début de la thèse : 2026-10-01 Date limite de candidature : 2026-05-22T23:59:59 One of the central challenges in quantum information processing is encoding quantum states in a way that remains robust against environmental noise. Topological quantum matter offers a way to avoid environmental noise by storing information non-locally, thereby protecting it from common sources of decoherence. However, despite this advantage, scalability remains a major obstacle, largely due to the limited tunability of existing experimental platforms.
Van der Waals (vdW) heterostructures provide a promising path forward thanks to their exceptional tunability, which enables precise control over key parameters such as interaction strength, symmetry breaking, and carrier density [1]. Their weak interlayer bonding allows pristine monolayers to be exfoliated and reassembled with well-defined relative orientation. Stacking and twisting introduce additional degrees of freedom; in particular, twisted bilayers form moiré superlattices that can induce band inversions and generate flat bands, where quenched kinetic energy strongly enhances interaction effects.
These features make vdW heterostructures ideal for exploring exotic phases arising from the interplay of correlations, symmetry, and topology. Graphene multilayers, for example, host quantum anomalous Hall (QAH) states and superconductivity [2-6], while proximitized graphene supports coherent chiral supercurrents [7-9]. Transition metal dichalcogenides (TMDs) exhibit strong spin-orbit coupling, Ising superconductivity [10-12], and a wide range of topological phases [13-20], including QAH states [21], with increasing evidence for topological superconductivity [22-29].
Beyond electronic tunability, stacking non-centrosymmetric monolayers can generate an out-of-plane ferroelectric polarization that switches via lateral sliding [30]. Recent experiments show that this stacking-induced ferroelectricity can coexist with metallic and superconducting phases [31,32], and can modulate both superconductivity and the topological band structure [33-35], enabling real-time control over topological phase transitions.
Develop a theoretical framework for emergent topological quantum phenomena in tunable van der Waals heterostructures. In particular, this work aims to elucidate how stacking and twisting vdW monolayers generate band crossings and enhance interactions, enabling the emergence and control of topological phases, as well as to characterize their boundary modes and dynamics. The aim of this thesis is to identify topological superconducting phases in vdW heterostructures and characterize their boundary modes and experimental signatures. A further goal is to determine experimental platforms that permit the dynamical control of these phases and their protected boundary modes for quantum information processing. Finally to analyze the transport behavior associated with such dynamical modulation, and to evaluate the sources of decoherence and dissipation that arise during the manipulations. Keldysh, BCS and self consistent gap equation, scattering matrix, renormalization group and related field theoretical techniques.

Mater's in physics. Good knowledge in solid-state physics and quantum many-body theory. Proficiency in Python.