Unconventional superconductivity
Pairing mechanisms in kagome metals, atomic layers, and nickelates
Superconductivity emerges when electrons form coherent pairs. My research investigates how electronic interactions, orbital character, and lattice geometry select the structure of those pairs. Using first-principles models and many-body calculations, I study alternatives to conventional phonon-mediated pairing and identify signatures that can help experiments distinguish competing superconducting states.
ciao Pairing on the kagome lattice
In the AV3Sb5 family (A = K, Rb, Cs), superconductivity develops in an electronic structure with several nearby van Hove singularities. Our Physical Review Letters (2021) study showed how the distribution of electronic states across kagome sublattices, together with nonlocal Coulomb repulsion, affects the favoured pairing symmetry. This provides a microscopic framework for understanding competing superconducting instabilities rather than assigning a universal pairing state to the entire family.
Nature of Unconventional Pairing in the Kagome Superconductors AV3Sb5 (A = K, Rb, Cs) · Physical Review Letters 127, 177001 (2021).
Triplet pairing in an atomic tin layer
A triangular layer of tin atoms on silicon offers a setting in which interactions between electrons on neighbouring sites matter strongly. Our Physical Review Letters (2022) calculations predict that these nonlocal repulsive interactions can favour spin-triplet pairing: an f-wave state at moderate hole doping and a p-wave state at higher doping within the model studied. This identifies a possible route to unconventional superconductivity in a material platform compatible with semiconductor substrates. The predicted pairing symmetry remains a question for experimental tests.
Triplet Superconductivity from Nonlocal Coulomb Repulsion in an Atomic Sn Layer Deposited onto a Si(111) Substrate · Physical Review Letters 128, 167002 (2022), Editors’ Suggestion.
Orbital-selective pairing in nickelates
In Physical Review B (2025), we developed a first-principles-guided description of infinite-layer LaNiO2 that includes both nickel and lanthanum orbitals. The calculations reveal competition between even-parity d-wave and odd-parity p-wave pairing. Strong renormalization of the nickel orbital’s quasiparticle weight can favour the p-wave channel, demonstrating how unequal correlation effects across orbitals can change the preferred superconducting state. This is a theoretical mechanism for triplet pairing, not an experimental identification of the order parameter.
Orbital-selective spin-triplet superconductivity in infinite-layer LaNiO2 · Physical Review B 112, L100503 (2025).
Across these systems, the central question is how the microscopic electronic structure selects a pairing mechanism and symmetry. This connects directly to my work on kagome metals and on machine learning for many-body physics.