Perpustakaan Digital ITB

The interplay between lattice gauge theories and fermionic matter accounts for fundamental physical phenomena ranging from the deconfinement of quarks in particle physics to quantum spin liquid with fractionalized anyons and emergent gauge structures in condensedmatter physics.However, except for certain limits (for instance, a large number of flavors of matter fields), analytical methods can provide few concrete results. Here we show that the problem of compact Uð1Þ lattice gauge theory coupled to fermionic matter in ð2 þ 1ÞD is possible to access via sign-problem-free quantum Monte Carlo simulations. One can hence map out the phase diagramas a function of fermion flavors and the strength of gauge fluctuations. By increasing the coupling constant of the gauge field, gauge confinement in the form of various spontaneous-symmetrybreaking phases such as the valence-bond solid (VBS) and N´eel antiferromagnet emerge. Deconfined phases with algebraic spin and VBS correlation functions are also observed. Such deconfined phases are incarnations of exotic states of matter, i.e., the algebraic spin liquid, which is generally viewed as the parent state of various quantumphases. The phase transitions between the deconfined and confined phases, aswell as that between the different confined phases provide various manifestations of deconfined quantum criticality. In particular, for four flavorsNf ¼ 4, our data suggest a continuous quantumphase transition between the VBS andN´eel order. We also provide preliminary theoretical analysis for these quantum phase transitions.