Efficient purification of a spin bath by an interacting ensemble of NV spins in diamond

The study of open quantum systems, quantum thermodynamics and quantum many-body spin physics in realistic solid-state platforms, has been a long-standing goal in quantum and condensed-matter physics. In this talk I will address these topics through the platform of nitrogen-vacancy (NV) spins in diamond, in the context of purification (or cooling) of a spin bath as a quantum resource and for enhanced metrology. I will first describe a general theoretical framework we developed for Hamiltonian engineering in an interacting spin system [1]. I will then extend this framework to coupling of the spin ensemble to a spin bath, including both coherent and dissipative dynamics [2]. Using these tools I will present a scheme for efficient purification of the spin bath, surpassing the current state-of-the-art and providing a path toward applications in quantum technologies, such as enhanced MRI sensing.