Triplon analysis of magnetic disorder and order in maple-leaf Heisenberg magnet

Abstract

Abstract The nearest-neighbor spin-1/2 Heisenberg model on the maple-leaf lattice formed by hexagons (coupling Jh ), triangles (coupling Jt ), and dimers (coupling Jd ), is investigated in a parameter regime where J h > 0 and J t , J d < 0 . This investigation aims to identify regions hosting exotic valence-bond solid states. Two potential magnetically disordered ground states are identified, and their stability is assessed through plaquette-triplon mean-field analyses. The resulting quantum phase diagram reveals that at large | J t | and | J d | , the system adopts a magnetically disordered dimerized VBS state, while for small | J d | , it stabilizes a Néel state. A second-order phase transition from the dimerized phase to a Néel phase is observed, which, being Landau-forbidden, suggests the potential presence of exotic phenomena such as a deconfined quantum critical point or the appearance of a quantum spin liquid. This work provides insights into the phase diagram of the nearest-neighbor spin-1/2 Heisenberg model on the maple-leaf lattice and lays the groundwork for further investigations into its intriguing physics.