Cavity QED in the ultrastrong-coupling regime & Landau-Zaner-Stückelberg interfereometry
The study of ground spaces of local Hamiltonians is a fundamental task
in condensed matter physics. In terms of computational complexity
theory, a common focus in this area has been to estimate a given
Hamiltonian’s ground state energy. However, from a physics
perspective, it is often more relevant to understand the structure of
the ground space itself. In this paper, we pursue the latter direction
by introducing the notion of “ground state connectivity” of local
Quantum technologies are widely expected to bring about many key technological advances this century. Quantum metrology and quantum information have been so far successfully applied in the design of devices that outperform their classical counterparts by exploiting quantum properties. Impressively, the quantum era is now reaching relativistic regimes. Table-top experiments demonstrate relativistic effects in quantum fields and long range quantum experiments will soon reach regimes where relativity kicks in.
Quantum entanglement is known to provide a strong advantage in many two-party distributed tasks. We investigate the question of how much entanglement is needed to reach optimal performance. For the first time we show that there exists a purely classical scenario for which no finite amount of entanglement suffices. To this end we introduce a simple two-party nonlocal game $H$, inspired by Hardy's paradox. In our game each player has only two possible questions and can provide bit strings of any finite length as answer.
Recently Yaoyun Shi and I gave the first proof of security for robust exponential quantum randomness expansion. This talk will be an overview of the problem and a discussion of the techniques used in our proof.
The lecturer will be Phil Kaye, a 2006 IQC graduate currently working at the Government of Canada. This lecture will be more informal and will focus on Phil's career path, how his PhD prepared him for his current position, and the challenges of working outside of academia.
For futher questions, please contact Corey Rae, IQC GSA President, crmcrae@uwaterloo.ca
We simultaneously generate photon-subtracted squeezed vacuum and squeezed vacuum at three frequencies from an optical parametric oscillator by utilizing its frequency non-degenerate sidebands. Quantum non-Gaussianity is demonstrated by applying a novel character witness.
How can one be certain that the output of an alleged random
number generator is indeed random? This question is important not
only for the efficiency and the security of information
processing, but also for understanding how intrinsically
unpredictable events are possible in Nature. Practical random
number generators have often been found to be insecure. All
existing theoretical solutions require a certain form of
independence among two or more sources of randomness, a condition
Recently, quantum circuits that are composed of unitary as well as probabilistic elements were employed for quantum synthesis and compilation tasks. In some cases, RUS designs led to implementations that on average are more efficient than the previously best known solutions based on unitary circuit designs. I will highlight some of the developments that are related to the synthesis of single-qubit operations and to the implementation of integer arithmetic on a quantum computer.
A conference to celebrate the work of Chris Godsil
It is surprising that the characteristic polynomial of
the adjacency matrix of a graph provides a useful window onto combinatorial properties of the graph itself, but this approach to graph theory has been a source of interesting and useful results for over 80 years.