Spin Non-commutativity and the Three-Dimensional Harmonic Oscillator
  A three-dimensional harmonic oscillator with spin non-commutativity in the phase space is considered. The system has a regular symplectic structure and by using supersymmetric quantum mechanics techniques, the ground state is calculated exactly. We find that this state is infinitely degenerate and it has explicit spontaneous broken symmetry. Analyzing the Heisenberg equations, we show that the total angular momentum is conserved. 
H. Falomir, J. Gamboa, M. Loewe, F. Mendez and J. C. Rojas
hep-th