Year: 2024
Type: article
Abstract: We introduce the concept of “quantum geometric nesting” (QGN) to characterize the idealized ordering tendencies of certain flat-band systems implicit in the geometric structure of the flat-band subspace. Perfect QGN implies the existence of an infinite class of local interactions that can be explicitly constructed and give rise to solvable ground states with various forms of possible fermion bilinear order, including flavor ferromagnetism, density waves, and superconductivity. For the ideal Hamiltonians constructed in this way, we show that certain aspects of the low-energy spectrum can also be exactly computed including, in the superconducting case, the phase stiffness. Examples of perfect QGN include flat bands with certain symmetries (e.g., chiral or time reversal) and non-symmetry-related cases exemplified with an engineered model for pair-density wave. Extending this approach, we obtain exact superconducting ground states with nontrivial pairing symmetry. Published by the American Physical Society 2024
Source: Physical Review X
Language: English
Topic: Quantum many-body systems
Subfield: Atomic and Molecular Physics, and Optics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $4,200
Funders: National Science Foundation, U.S. Department of Energy, Gordon and Betty Moore Foundation, European Commission, United States-Israel Binational Science Foundation, Horizon 2020 Framework Programme, Office of Naval Research, Division of Materials Research, Basic Energy Sciences, H2020 European Research Council
Awards: G1417316065, G1426273466, G1746067696, G231474785, Emergent Phenomena in Quantum Systems Theory Center, G303061748, Second Phase of the QuantEmX Scientist Exchange Program, G434337789, G5096419125, G5271502856, QuantERA II ERA-NET Cofund in Quantum Technologies, G5947738484, G6140129497, G6536552022, Princeton Center for Complex Materials, G8876996369, G911061179
OpenAlex ID: W4403147387