Modelling quantum materials at mesoscopic and macroscopic scales requires tight-binding calculations far too large for explicit matrices, a bottleneck for moiré and super-moiré heterostructures and quasicrystals. QMAT researchers at Aalto University present a unified tensor-network methodology that maps a system of 2L sites onto a many-body problem of just L pseudospins.
For Hamiltonians with compressible real-space structure, the cost stays modest whatever the system size. The authors demonstrate spectral functions, momentum-space spectra, topological invariants, real-time dynamics, mean-field symmetry breaking, non-Hermitian phenomena and excitons in systems with billions of sites. The method is released as the open-source Julia package TensorBinding. The authors are Tiago Antão, Anouar Moustaj, Yitao Sun and Jose Lado of the Correlated Quantum Materials group.
The preprint has not yet been peer reviewed.
Image: QMAT