JQI

The approximate stabilizer rank of a quantum state is the minimum number of terms in any approximate decomposition of that state into stabilizer states. We expect that the approximate stabilizer rank of n-th tensor power of the “magic” T state scale exponentially in n, otherwise there is a polynomial time classical algorithm to simulate arbitrary polynomial time quantum computations.  Despite this intuition, several attempts using various techniques could not lead to a better than a linear lower bound on the “exact” rank.

We discuss recent progress on entanglement catalysis, including the equivalence between catalytic and asymptotic transformations of quantum states and the impossibility to distill entanglement from states having positive partial transpose, even in the presence of a catalyst. A more general notion of catalysis is the concept of entanglement battery. In this framework, we show that a reversible manipulation of entangled states is possible. This establishes a second law of entanglement manipulation without relying on the generalized quantum Stein's lemma.

Light is quantum. Hence, quantifying and attaining fundamental limits of transmitting, processing and extracting information encoded in light must use quantum analyses. This talk is aimed at elucidating this using principles from information and estimation theories, and quantum modeling of light. We will discuss nuances of “informationally optimal” measurements on so-called Gaussian states of light in the contexts of a few different metrics.

Dissertation Committee Chair: Mohammad Hafezi

Committee: 

Glenn Solomon

Jay Sau

Nathan Schine

You Zhou

Ichiro Takeuchi (Dean’s representative)

Dissertation Committee Chair: Prof. Steve Rolston

Committee: 

Prof. Gretchen Campbell

Prof. Nathan Schine

Prof. Ron Walsworth

Prof. Ki-yong Kim

Statistical learning is emerging as a new paradigm in science.

This has ignited interest within our inherently quantum world in exploring quantum machines for their advantages in learning, generating, and predicting various aspects of our universe by processing both quantum and classical data. In parallel, the pursuit of scalable science through physical simulations using both digital and analog quantum computers is rising on the horizon.

Dissertation Committee Chair: Professor Christopher R. Monroe

Committee:                       

Professor Alexey V. Gorshkov

Professor Zohreh Davoudi

Professor Norbert M. Linke

Professor Christopher Jarzynski