Related papers: $\mathbb{Z}_2$ gauge theory for valence bond solid…
Condensed matter physicists have long sought a realistic two-dimensional (2D) magnetic system whose ground state is a {\it spin liquid}---a zero temperature state in which quantum fluctuations have melted away any form of magnetic order.…
Motivated by the recent discovery of charge density wave (CDW) order in the magnetic kagom\'e metal FeGe, we study the single-orbital $t$-$U$-$V_1$-$V_2$ model on the kagom\'e lattice, where $U$, $V_1$, and $V_2$ are the onsite, nearest…
In Volborthite, spin-1/2 moments form a distorted Kagom\'e lattice, of corner sharing isosceles triangles with exchange constants $J$ on two bonds and $J'$ on the third bond. We study the properties of such spin systems, and show that…
We use Quantum Monte-Carlo methods to study the ground state phase diagram of a S=1/2 honeycomb lattice magnet in which a nearest-neighbor antiferromagnetic exchange J (favoring N\'eel order) competes with two different multi-spin…
We study the kagome antiferromagnet for quantum spin-1/2 with first J1, second J2 and third J3 neighbour exchanges, along the J2 = J3 = J line. We use Schwinger-boson mean-field theory for the precise determination of the phase diagram, and…
Zn-Paratacamite is a rare spin 1/2 antiferromagnetic insulator with an ideal kagome lattice structure in part of its phase diagram. As a function of Zn doping, this material undergoes a structural distortion which relieves the frustration…
We study the phases of a spin system on the Kagome lattice with nearest-neighbor $XXZ$ interactions with anisotropy ratio $\Delta$ and Dzyaloshinsky-Moriya interactions with strength $D$. In the classical limit where the spin $S$ at each…
We study the superfluid-insulator transitions of bosons on the Kagome lattice at incommensurate filling factors f=1/2 and 2/3 using a duality analysis. We find that at f=1/2 the bosons will always be in a superfluid phase and demonstrate…
Spin-1/2 kagome-lattice Heisenberg antiferromagnet is theoretically known to have a quantum spin liquid ground state, one of the frontiers of condensed matter physics. The search for the model substances has been continued for a long time,…
We examine the stability of the valence bond solid (VBS) phase against the Dzyaloshinskii-Moriya (DM) interaction in the bipartite lattice. Despite the VBS is vulnerable against the antiferromagnetic interaction, for example in the Q-J…
We present a study of a simple model antiferromagnet consisting of a sum of nearest neighbor SO($N$) singlet projectors on the Kagome lattice. Our model shares some features with the popular $S=1/2$ Kagome antiferromagnet but is…
Realizing a quantum spin liquid (QSL) ground state in a real material is a leading issue in condensed matter physics research. In this pursuit, it is crucial to fully characterize the structure and influence of defects, as these can…
Recently, thermal Hall effect has been observed in the paramagnetic state of Volborthite, which consists of distorted Kagome layers with $S=1/2$ local moments. Despite the appearance of a magnetic order below $1 \, \mathrm{K}$, the response…
The search for the resonating valence bond (RVB) state continues to underpin many areas of condensed matter research. The RVB is made from the dimerisation of spins on different sites into fluctuating singlets, and was proposed by Anderson…
The theory for the vanishing of N\'eel order in the spin $S=1/2$ square lattice antiferromagnet has been the focus of attention for many decades. A consensus appears to have emerged in recent numerical studies on the antiferromagnet with…
Spin-1/2 kagome antiferromagnet (AFM) is one of the most studied models in frustrated magnetism since it is a promising candidate to host exotic spin liquid states. However, despite numerous studies using both analytical and numerical…
SU(2) lattice gauge theory is studied after eliminating thin monopoles and the smallest thick monopoles. Kinematically this constraint allows thick vortex loops which produce long range Z(2) fluctuations. The thick vortex loops are…
We demonstrate the existence of semivortex (SV) solitons, with vorticities $0$ and $1$ in the two components, in a two-dimensional (2D) fermionic spinor system under the action of the Rashba-type spin-orbit coupling in the combination with…
We propose an efficient variational method for $Z_2$ lattice gauge theory based on the matrix product ansatz. The method is applied to ladder and square lattices. The Gauss law needs to be imposed on quantum states to guarantee gauge…
Quantum fluctuations of the N\'eel state of the square lattice antiferromagnet are usually described by a $\mathbb{CP}^1$ theory of bosonic spinons coupled to a U(1) gauge field, and with a global SU(2) spin rotation symmetry. Such a theory…