Events

RAC Journal Club Series featuring Bhaskaran Muralidharan, Indian Institute of Technology, Bombay

Join us for Quantum Today, where we sit down with researchers from the University of Waterloo’s Institute for Quantum Computing (IQC) to talk about their work, its impact and where their research may lead.

Developments in device-independent cryptography

Device-independent cryptography connects the foundational topic of Bell inequalities to the operational task of achieving secure cryptography. With significant progress being made in Bell test experiments, various avenues for further developing device-independent cryptography have been opened. I will give an overview of some background and recent developments in the field, as well as some research questions that should be of interest going forward.

IQC Alum Lecture Series: Urbasi Sinha, Raman Research Institute

In this talk, we cover different interesting aspects of experimental photonic quantum information processing that have been recently explored at the Quantum Information and Computing lab at RRI, Bangalore. We discuss our experiment on the first loophole free violation of the Leggett Garg Inequalities (LGI) as well as the Wigner form of the same (WLGI)[1].

Julien LAURAT (ENS Paris)

Quantum interconnects are central to the scale up of quantum information architectures. In this endeavour, I will first report on the implementation of a highly-efficient quantum memory based on a large ensemble of cold atoms. I will discuss how we implemented such efficient memories over the recent years, from typical efficiency values of about 30% in 2015 to 70% in 2018 and close to 90% in this recent work. Moreover, we used this platform to demonstrate highly efficient and reversible entanglement transfer into and out of two quantum memories. I will also present the realization of a faithful quantum-bit-encoding converter that relies on a teleportation process based on hybrid entanglement of light between CV and DV optical qubits.

Chris Ferrie, University of Technology Sydney and the Centre for Quantum Software and Information

Although most of us don't actually understand quantum physics, we know that it's mystical and awesome, and if we understood it we'd probably be rich and beautiful and happy, right? After all, there are plenty of people out there trying to sell you quantum crystals to align your quantum energy with your quantum destiny. Can they all be wrong? Yes, yes they can. In this talk, we're going to sniff out the bullshit and break down why it stinks while dispelling the mystery of the quantum.

Generation and detection of spin-orbit coupled neutron beams

Structured waves and spin-orbit coupled beams have become an indispensable probe in both light and matter-wave optics [1-2], for neutron specifically, showing distinct scattering dynamics for some samples [3-4]. We present a method of generating neutron orbital angular momentum (OAM) states utilizing 3He neutron spin filters along with four specifically oriented triangular coils and magnetic field shielding. These states are verified via their spin-dependent intensity profiles [5]. The period and OAM number of these spin-orbit states can be altered dynamically via the magnetic field strength within the coils and the total number of coils to tailor the neutron beam towards a particular application or specific material [6].

The Office of Research at the University of Waterloo will be hosting a webinar to provide practical information and answer questions related to the new NSERC Alliance funding options that support Canada’s National Quantum Strategy.

Dissipative landau Zener transition in the weak and strong coupling limits

Landau Zener (LZ) transition is a paradigm to describe a wide range of physical phenomenon. Dissipation is inevitable in realistic devices and can affect the LZ transition probabilities. I will describe how we can model the effect of the environment depending on whether it is weakly or strongly coupled to the system. I will also present our experimental results where we found evidence of crossover from weak to strong coupling limit.

The optimal rates for compression of mixed states was found by Koashi and Imoto in 2001 for the blind case and by Horodecki and independently by Hayashi for the visible case respectively in 2000 and 2006. However, it was not known so far whether the strong converse property holds for these compression problems. In this work, we show that the strong converse holds for the blind compression scheme. For the visible scheme, the strong converse holds up to the continuity of the regularized Renyi entanglement of purification.