Choi, Joonhee2019-12-122019-052019-04-302019Choi, Joonhee. 2019. Quantum Many-Body Dynamics of a Disordered Electronic Spin Ensemble in Diamond. Doctoral dissertation, Harvard University, Graduate School of Arts & Sciences.http://nrs.harvard.edu/urn-3:HUL.InstRepos:42029771A strongly interacting driven spin system can display a variety of interesting many- body quantum phenomena due to the interplay of interaction, disorder and coherent driving. Using a dense electronic spin ensemble of atom-like impurities in diamond, we study non-equilibrium quantum many-body dynamics involving ∼10^6 spins. Specifically, we describe: (1) investigation of thermalization dynamics of a closed quantum system in the presence of long-range interactions and on-site disorder, (2) realization of new non-equilibrium phases of matter, such as discrete time crystals, and (3) probing emergent phase transitions in a driven many-body system. In addition, the high-density spin ensembles in the solid state also show great promise for practical sensing applications. As a practical application of these studies, we demonstrate high sensitivity magnetic-field sensing with fault-tolerant pulsed control. These studies demonstrate that dense electronic spin ensembles in the solid state can be a powerful tool to simulate quantum many-body dynamics, explore new coherent non-equilibrium phenomena and to detect external signals with superior sensitivity and high spectral and spatial resolution.application/pdfenFloquet systemsLong-range interactionsQuantum opticsArtificial atomsNitrogen-Vacancy centersCritical phenomenaSpin relaxationNonequilibrium dynamicsQuantum sensingQuantum phase transitionSpontaneous symmetry breakingThesis or Dissertation2019-12-12