Speaker
Description
Low-dimensional quantum magnets are of great fundamental importance due to strong quantum fluctuations which can produce novel quantum excitations and ground states. The 2D quantum (S = 1/2) Heisenberg antiferromagnet on a square lattice (2DQHAFSL) is one of the canonical interacting quantum systems. The chiral quantum magnet family A(bO)CU4(PO4)4 shows great promise to be a very exciting system to study novel quantum magnetism, where A-b = Ba-Ti, Pb-Ti, Sr-Ti and Ba-V. Indeed, substitution of A2+ cation controls the strength of the structural chirality in this family and shows a dramatic change in the magnetic interactions. This defines a family of chiral magnets with a tunable crystal structure.
These compounds crystallises in layers of Cu4O16 cupolas that stack along the (00L) direction. Our hope is that it is a good approximation of the square lattice, depending on the chirality of the system.
In this presentation, I will show the results of our neutron scattering measurements on several members of this family. An hamiltonian has been derived based on a Multi Bosonic Wave Theory. I will then include our compounds in the frame of the analysis of the J1-J2 Heisenberg model on the square lattice phase diagram.
