Speaker
Description
Quantum link models (QLMs) are extensions of Wilson-type lattice gauge theories, and show rich physics beyond the phenomena of conventional Wilson gauge theories. Here we explore the physics of U(1) symmetric QLMs, both using a more conventional quantum spin-1/2 representation, as well as a fermionic representation. In 2D, we show that both bosonic and fermionic QLMs have the same physics. We then explore the models in 3D and find different behavior for the two QLMs. For the bosons, we see evidence for a quantum phase transition from a broken phase to a quantum spin liquid, but for the fermions, we identify not one but two distinct phases in addition to the fermionic broken phase. We explore the symmetries of the ground state in the broken phase strong coupling limit, and explain the spectrum for both models. The phase transitions are confirmed through scaling of the gaps as well as the ground state fidelity susceptibilities.
