Discontinuous spin-glass transition in a random quantum Heisenberg magnet

We study the Schwinger bosons SU(M) generalization of the spin-S (S{≡}{κ}M) quantum Heisenberg magnet with infinite-range, Gaussian-random exchange interactions. The spin-glass transition was accessed in the spherical limit M={∞} with fixed {κ}. The model is solved exactly in the spin-glass phase wthin the Parisi ansatz with a single step of the replica symmetry breaking. The physical consequences of this quantum spin-glass transition scenario are discussed.