Events

Neutron whispering gallery

Dr Valery Nesvizhevsky, European Centre for Neutron Research, Institut Laue-Langevin

The "whispering gallery" effect has been known since ancient times for sound waves in air, later in water and more recently for a broad range of electromagnetic waves: radio, optics, Roentgen and so on. It consists of wave localization near a curved reflecting surface and is expected for waves of various natures, for instance, for atoms and neutrons. For matter waves, it would include a new feature: a massive particle would be settled in quantum states, with parameters depending on its mass. In 2010, we observed the quantum whispering gallery effect for cold neutrons and since then continue increasing the precision in these experiments.

Li Liu

Entanglement is a type of resource used in quantum information theory that gives correlations that cannot be simulated using classical probability theory. It is known that entanglement cannot be created locally. 

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.

Dhinakaran Vinayagamurthy

Trusted-execution environments (TEE) like Intel SGX provide a promise for practical secure computations on users' sensitive data in untrusted computing environments like cloud and blockchains. TEEs are designed using a combination of hardware enforced access controls and cryptography. While there is extensive research on attacking and hardening the access control mechanisms, the advent of quantum computers also requires hardening the cryptography used by TEEs for their long-term security against quantum adversaries.

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.

Nadine Stritzelberger

In this seminar I will discuss my research, which is concerned with three different topics in the related fields of Quantum Theory, General Relativity and Cosmology.

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. 

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).

Justin Thaler, Georgetown University

The quantum query complexity of a function f measures how many bits of the input a quantum computer must look at in order to compute f. 

Neil Turok, Perimeter Institute

Observations reveal the cosmos to be astonishingly simple, and yet deeply puzzling, on the largest accessible scales. Why is it so nearly symmetrical? Why is there a cosmological constant (or dark energy) and what fixes its value? How did everything we see emerge from a singular “point” in the past?