These lecture notes introduce quantum spin systems and several computational methods for
studying their ground‐state and finite‐temperature properties. Symmetry‐breaking and …

The use of artificial neural networks to represent quantum wave functions has recently
attracted interest as a way to solve complex many-body problems. The potential of these …

We perform highly accurate density matrix renormalization group (DMRG) simulations to
investigate the ground-state properties of the spin-1/2 antiferromagnetic square lattice …

Using ground-state projector quantum Monte Carlo simulations in the valence-bond basis, it
is demonstrated that nonfrustrating four-spin interactions can destroy the Néel order of the …

Quantum spin liquids (QSLs) as novel phases of matter with long-range entanglement and
deconfined quantum critical points (DQCPs) as descriptions for unconventional phase …

We study the spin-1/2 Heisenberg model on the square lattice with first-and second-
neighbor antiferromagnetic interactions J 1 and J 2, which possesses a nonmagnetic region …

The nature of the zero-temperature phase diagram of the spin-1/2 J 1-J 2 Heisenberg model
on a square lattice has been debated in the past three decades, and it remains one of the …

We use the density matrix renormalization group method to calculate several energy
eigenvalues of the frustrated S= 1/2 square-lattice J 1-J 2 Heisenberg model on 2 L× L …

Strongly interacting quantum systems described by non-stoquastic Hamiltonians exhibit rich
low-temperature physics. Yet, their study poses a formidable challenge, even for state-of-the …

By direct calculations of the spin gap in the frustrated Heisenberg model on the square
lattice, with nearest-(J 1) and next-nearest-neighbor (J 2) super-exchange couplings, we …