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

Abstract:
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.

Biography:
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..