Controlling orbital magnetism of band electron systems via bath engineering

Orbital magnetism arises due to the coherent cyclotron motion of band electrons. System-bath entanglement is expected to disrupt this coherent electronic motion and quench orbital magnetism. Here, we show that a suitably tailored bath can lead to an enhancement of the orbital diamagnetic susceptibility of a multiband electron system and can even convert an orbital paramagnetic response into a diamagnetic one as the system-bath coupling is increased. We also demonstrate how a van Hove singularity in the bath density of states can be exploited to generate a giant enhancement of the orbital magnetic susceptibility. Our work opens doors to the possibility of controlling the orbital magnetic response of band electron systems through bath engineering.