Angular momentum of open quantum systems in external magnetic field

The non-Markovian dynamics of a charged harmonic oscillator linearly coupled to a neutral bosonic heat bath is investigated in external uniform magnetic field. The analytical expression is derived for the asymptotic angular momentum. The orbital diamagnetism of quantum system in a dissipative environment is studied.

Figure 1

Calculated magnetic-field dependence of the asymptotic $z$ component $L_z$ of angular momentum at temperature $T/\left(\hslash \lambda \right)=0.1$ (a) or $T/\left(\hslash \lambda \right)=2$ (b) and fixed ${\lambda }_x={\lambda }_y=\lambda , \gamma /\lambda =12$. The solid, dashed, dotted, and dash-dotted lines correspond to the cases with ${\omega }_0/\lambda =0$, 0.5, 1, and 2, respectively.