Group Seminar

We investigate the emergence of electronic order and unconventional superconductivity in $M$-valley moiré materials at weak coupling.
Starting from a first-principles Wannier model of AB-stacked twisted SnSe2, we tackle the gate-screened long-ranged Coulomb interaction using unbiased functional renormalization group simulations that resolve the momentum structure and energy scales of the leading Fermi surface instabilities.
We find that upon doping an antiferromagnetic stripe state at half-filling of the moiré flat bands, magnetic order gives way to unconventional superconductivity mediated by valley-selective spin fluctuations: electron doping stabilizes a spin-singlet, extended $s$-wave state that benefits from scattering between virtual particle and hole states that are detuned from the Fermi level, whereas hole doping favors spin-triplet, $p$-wave pairing. These findings establish M-point moiré materials as a quantum simulation platform with phenomenological parallels to the class of iron pnictide superconductors, though they are set apart from each other by the strong intravalley character and reduced dimensionality unique to the M-twisted systems.