Creating and sharing knowledge for telecommunications

Light-matter entanglement over 50 km of optical fibre

on 16-07-2019

... Ben Lanyon, Institute for Quantum Optics and Quantum Information and the University of Innsbruck

Date & time: Tuesday, July 16th, 15:00h
Location: Sala de formação avançada, 2nd floor of the Physics Department building, IST

When shared between remote locations, entanglement opens up fundamentally new capabilities for science and technology. Envisioned quantum networks use light to distribute entanglement between their remote matter-based quantum nodes. In this short talk, I will present our observation of entanglement between matter (a trapped ion) and light (a photon) over 50 km of optical fibre [1]: two orders of magnitude further than the state of the art and a practical distance to start building large-scale quantum networks. Our methods include an efficient source of ion-photon entanglement via cavity-QED techniques (0.5 probability on-demand fibre-coupled photon from the ion) and a single photon quantum frequency converter to the 1550 nm telecom C band (0.25 fibre-coupled device efficiency). Modestly optimising and duplicating our system could allow for 100 km-spaced ion-ion entanglement at rates over 1 Hz. Our results therefore show a path to entangling remote registers of quantum-logic capable trapped-ion qubits, and the optical atomic clock transitions that they contain, spaced by hundreds of kilometres. More Information..

Quantum Simulation with quantum computers

on 10-07-2019

... Joaquin Fernandez Rossier, International Iberian Nanotechnology Laboratory, in Braga, Portugal

Date & time: Wednesday, July 10th, 10:00h
Location: Instituto Superior Técnico, Lisbon, Room P3.10, Mathematics Building

In this seminar Joaquin Rossier will do 3 things:
He will review why quantum many-body problem is very important and can not be dealt with using classical computers;
He will discuss the use of digital quantum computers to tackle the many body problem;
He will discuss our quantum computations for quantum simulation of simple model Hamiltonians using IBM quantum hardware.

Joaquin Rossier is a condensed matter physicist. He holds both a Diploma (1994) and a Phd (1999) on Physics from the Universidad Autónoma de Madrid. He stayed 2 years (99-01) as a postdoctoral researcher at the Physics Department of the University of California San Diego and 18 months (01-03) at the Physics Department of the University of Texas at Austin. In 2003 he obtained a "Ramon y Cajal" assistant professor position in the Universidad de Alicante (UA). He was promoted to a permanent position in 2008 and to associate professor (professor titular) in 2009. Since 2011 he is on leave from the UA and holds a tenured research staff position at the INL (Braga, Portugal). More Information..