Faculty

Friday, December 7, 2018 2:00 pm - 2:00 pm EST (GMT -05:00)

Quantum Advantage in Learning Parity with Noise

Daniel Kyungdeock Park, Korea Advanced Institute of Science and Technology

Machine learning is an interesting family of problems for which near-term quantum devices can provide considerable advantages. In particular, exponential quantum speedup is recently demonstrated in learning a Boolean function that calculates the parity of a randomly chosen input bit string and a hidden bit string in the presence of noise, the problem known as learning parity with noise (LPN).

Li Liu

Following my previous seminar talk on embezzlement of entanglement, this talk introduces a more general version of the problem — self-embezzlement. Instead of embezzling a pair of entangled state from a catalyst, self-embezzlement aims to create two copies of the catalyst state using only local operators. 

Friday, November 30, 2018 11:00 am - 11:00 am EST (GMT -05:00)

Estimating outcome probabilities of quantum circuits using quasiprobabilities

Hakop Pashayan, The University of Sydney

We present a method for estimating the probabilities of outcomes of a quantum circuit using Monte Carlo sampling techniques applied to a quasiprobability representation. Our estimate converges to the true quantum probability at a rate determined by the total negativity in the circuit, using a measure of negativity based on the 1-norm of the quasiprobability. If the negativity grows at most polynomially in the size of the circuit, our estimator converges efficiently.

Thursday, November 29, 2018 1:30 pm - 1:30 pm EST (GMT -05:00)

Using macroscopic quantum systems as detectors

Swati Singh, University of Delaware

When properly engineered, simple quantum systems such as harmonic oscillators or spins can be excellent detectors of feeble forces and fields. Following a general introduction to this fast growing area of research I will focus on two simple and experimentally realizable examples: a nitrogen vacancy (NV) center in diamond interacting with its many-body environment, and acoustic modes of superfluid helium interacting with gravitational waves.

Tuesday, November 27, 2018 1:00 pm - 1:00 pm EST (GMT -05:00)

Dynamical control of superconductors and ultracold atoms

Ludwig Mathey, University of Hamburg

While traditional means of influencing material properties are static, I will present our recent studies of dynamical control of high-temperature superconductors via light pulses. Specifically, I will discuss both light enhanced superconductivity, for which we propose a parametric amplification mechanism, as well as light induced superconductivity. As a second platform, I will describe dynamics in driven cavity-BEC systems.