Events

Topological cavity states in two-dimensional photonic/phononic chips

Jian-Hua Jiang, School of Physical Science and Technology, Soochow University

Topological insulators are electronic systems with an insulating bulk and topologically protected boundary states. Conventional 2D topological insulators induce 1D edge states. Recent studies indicate that lower-dimensional topological states are also possible in electronic systems, which, however, has been confirmed only in Bismuth in experiments [1].

Raymond Laflamme, Department of Physics and Astronomy; Institute for Quantum Computing

Stephen Hawking passed away leaving behind a transformed view of the cosmos. He proved that time had a beginning if Einstein's general relativity is correct, that black ain't so black after all and he proposed that the Universe can be described by a quantum mechanical wave function with no edge or boundaries. From 1984 to 1988 I was one of Stephen's graduate students and worked on quantum cosmology and the arrow of time which earned me a quote in the book: "A Brief History of Time".

QUANTUM + Pop Culture

“Quantum physics” has taken its position with “rocket science” in pop culture as a shorthand for frighteningly complicated science. Quantum physics has also taken on a sort of magical connotation in fiction, with features like entanglement, superposition, and tunneling spurring imagination. But where does the science draw the line? How much is joyful speculation, and how much is disregard for reality? And if it’s always seen as either magical or scary, how does that affect the perception of quantum science?

Henry Yuen, University of Toronto

An outstanding open question in quantum information theory concerns the computational complexity of nonlocal games. in a nonlocal game, a classical verifier interacts with multiple players that cannot communicate, but are allowed to share entanglement. In a recent breakthrough result, Slofstra showed that the following problem is undecidable: given a nonlocal game, is there a quantum strategy for the players to win with probability 1?

Jun Fan, City University of Hong Kong

Two-dimensional nanomaterials could cause structural disruption and cytotoxic effects to cells, which greatly challenges their promising biomedical applications including biosensing, bioimaging, and drug delivery. Here, interactions between lipid liposomes and hydrophobic nanosheets is studied utilizing coarse-grained (CG) molecular dynamics (MD) simulations. The simulations reveal a variety of interaction morphologies that depend on the size and the orientation of nanosheets.

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.

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.

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.

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.

Methods for parallel quantum circuit synthesis, fault-tolerant quantum RAM, and quantum state tomography

PhD Candidate: Olivia Di Matteo
Supervisor: Michele Mosca

Thesis available from the Science graduate office, PHY 2013.

Oral defence in QNC B204.