Dresden 2026 – scientific programme

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TT: Fachverband Tiefe Temperaturen

TT 13: Correlated Electrons: Method Development I

TT 13.6: Talk

Monday, March 9, 2026, 16:15–16:30, HSZ/0101

Dimer Hubbard operators and their applications — •Jie Xiong and Silke Biermann — CPhT, Ecole Polytechnique, Palaiseau, France

Hubbard operators, introduced in the 1960s as projectors between atomic many-body eigenstates [1], serve as quasiparticle operators that naturally represent the lower and upper Hubbard bands. They also provide one of the earliest systematic approaches for calculating Green’s functions in the Hubbard model. Extending this approach, we construct quasiparticle operators for the dimer Hubbard model and propose a general framework for analyzing quasiparticle operators in interacting many-body systems with periodic boundary conditions. As an application, we derive the equations of motion for the dimer Hubbard operators and compute Green’s functions for finite benchmark models. Our findings suggest broad prospects for extending the quasiparticle-operator construction to larger correlated systems and exploring its potential applications in topological phases.
[1] J. Hubbard, Proc. R. Soc. Lond. A 276, 238 (1963).

Keywords: Quasiparticle operators; Green’s functions; Many-body theory