LF musr study of magnetic phases and spin dynamics in a Shastry-Sutherland Quantum Magnet

In 2D magnetic compounds, the Shastry-Sutherland lattice (SSL) – a square lattice with an antiferromagnetic exchange J between dimerized nearest neighbours and J’ between next-nearest-neighbours, has attracted attention due to its complex phase diagram, displaying a variety of novel phases as function of magnetic field. The 2D SSL model, consisting of an orthogonal dimer network of spin S=1/2, represents one of the very few topologies where the ground state of a geometrical frustrated lattice could be exactly solved. Previous experimental realizations of the SSL model such as SrCu2(BO3)2 (SCBO) exhibit multiple magnetization plateaus at fractional values, but the critical fields have previously been much too large for muSR studies. Lately, a new rare-earth SSL compound Er2Be2GeO7 with weaker interactions that SCBO was found to show magnetization plateaus with critical fields below 1T, giving the first opportunity for muSR to provide a local probe study of the magnetic properties of the SSL lattice.