Ph.D. Physics – University of Michigan, 2009
Dr. Kestner was previously a postdoctoral researcher in the Condensed Matter Theory Center at the University of Maryland, College Park (2009-2012)
I am interested in developing useful physical devices that exploit the strange features of quantum mechanics. A prominent example is a quantum computer, which could solve a certain important class of problems exponentially faster than any computer based on the current classical bit model. My work is theoretical, and focuses on experimentally available systems that present distinctly quantum behavior: ultracold gases of atoms or polar molecules, and “artificial” atoms and molecules, i.e., quantum dot systems in solid state materials.
My work on semiconductor quantum dots involves designing protocols to precisely control (despite a noisy environment) the spin state of one or more electrons trapped in the dots. This is an important problem, since electron spins in quantum dots can be used as building blocks in a quantum computer, and experiments are currently limited by spin dephasing. This is a common problem in many contexts (such as nuclear magnetic resonance) but the quantum dot system imposes very strict constraints on the control capabilities, ruling out the common solutions (such as BB1). Recently, I have developed new forms of composite pulse sequences that self-correct for the types of error believed to be the most relevant experimentally.