IQUPS - Ingénierie quantique

Geographic repartition of the participating laboratories (area of disks proportional to the number of permanent researchers involved in IQUPS) :

In the second phase of IQUPS, laboratories which are not any more attached to Université Paris-Saclay (CPhT, LSI, LTCI) cannot receive any support from IQUPS. They are however welcome to participate to the activities of IQUPS.

Teams involved in IQUPS, with the name of the correspondant(s) and links to the websites :

Because of the high level of international competitiveness, reactivity to explore new research and engineering directions is mandatory. We want to favor the emergence of new ideas by supporting small risky projects, in particular those emerging from collaborations within UPSay triggered by IQUPS. This support is designed to give the initial kick to help maturation and obtain further funding (Labex, ANR). In 2017, the board of IQUPS selected 4 projects (presented below) after a call to all the participating teams. The selection was based on the criteria of novelty, absence of other funding, competition, risk, and of course adequacy with the objectives of IQUPS.

Since 2018, IQUPS coordinates with the DIM SIRTEQ:

In 2018, two projects from IQUPS teams, ALAPAGE and DROPLETS, were selected by SIRTEQ and co-funded by IQUPS (25k€ each).

In 2019, IQUPS proposed a co-financing to projects funded after the SIRTEQ call "small and medium equipment". The following projects are supported: LASANTI by Daniel Comparat (LAC) (18000€); CONFITUR by Philippe Delaye (LCF) (8750€); KISPPD by Julien Gabelli (LPS) (15000€); VORTEXMIX by Quentin Glorieux (LKB), involving Laurence Pruvost (LAC) (12000€); SPINDIAM by Gabriel Hétet (LPENS), involving Loïc Rondin (LAC) (9000€); and MOHIQUAN by Philippe Joyez (SPEC) (20419€). In addition, two post-docs will be supported for 11 months by IQUPS, in addition to their support by SIRTEQ: Daniel Flanigan at SPEC (with Hélène le Sueur), and Amrendra Pandey at LAC (with Olivier Dulieu).

IQUPS organize series of courses, with each time 4 mornings with two different courses in a row.

5th series (26 November, 10, 12, 17 December 2019):

Quantum fluids of light by Jacqueline Bloch (C2N, Palaiseau) and Quentin Glorieux (LKB, Paris)
Open Quantum Systems: Foundations and Applications by Laurent Sanchez-Palencia (Centre de Physique Théorique, Institut Polytechnique de Paris, Palaiseau)

Abstracts:

Open Quantum Systems: Foundations and Applications (by Laurent Sanchez-Palencia)

The dramatic progress in the design of materials and synthetic simulators now allows to realize controlled quantum systems rather well isolated from their environment.
Yet, the coupling to the environment (bath) cannot be ignored and open systems are ubiquitous in Nature. It gives rise to a rich competition between coherence and dissipation, and novel dynamical effects. While coupling a system to a bath typically yields decoherence, recent works have shown that dissipation can be engineered to control many-body systems and engineer quantum entanglement.
The aim of this course is to give an introduction to open quantum systems.
We shall introduce the formalism and discuss applications to quantum technologies.

Lecture 1: Open systems and stochastic processes

Lecture 2: Master equation formalism: Kraus operators and Lindblad form

Lecture 3: Stochastic Schrödinger equation and quantum trajectories

Lecture 4: Engineered dissipation as a resource for entanglement

Quantum fluids of light (by Jacqueline Bloch and Quentin Glorieux)

When confining photons in semiconductor lattices, it is possible to strongly modify their physical properties. Photons can behave as finite or even infinite mass particles, photons can propagate along edge states without back scattering, photons can become superfluid and behave as massive interacting particles. These are just a few examples of properties that we can imprint into fluids of light in semiconductor lattices.  Such manipulation of light present not only potential for applications in photonics, but great promise for fundamental studies.  One can invent artificial media with very exotic physical properties at the single particle level and progress toward the generation of multi photons correlated states. One can also simulate complicated Hamiltonians with light to explore problems not accessible with ultra cold atoms.

• The three first lectures will be delivered by Jacqueline Bloch and dedicated to the physics of quantum fluids of light(also called polaritons) in semiconductor microcavities.
• Quentin Glorieux, LKB, Paris will give the last lecture and describe a different platform for the study of quantum fluids based on photons propagating through a hot vapor of Rubidium atoms in the paraxial approximation

Lecture 1 (J. Bloch): Introduction to cavity polaritons, linear properties and lattice engineering

Lecture 2 (J. BLoch): Polariton superfluidity and Bose Einstein condensation

Lecture 3 (J. Bloch): Emulation of different Hamiltonians using polariton lattices; perspectives for quantum correlations

Lecture 4 (Q. Glorieux) : Quantum fluids of light in hot atomic vapor : propagating geometries

Quantum Future Academy (24-31 August 2019)

Itinerant French-German workshop for 30 selected Licence/Master students (15 from France, 15 from Germany), taking place in Karlsruhe, Sarrebrücken, Strasbourg and Paris-Saclay. Announcement very soon.

One year of IQUPS (2 March 2018)

General meeting of IQUPS;

Recent advances in Quantum Computing (13-14 December 2017)

Building a universal quantum computer is considered as one of the most challenging goals of modern physics by making real and at the same time questioning many fundamental aspects of quantum mechanics.

The biggest issue is that the quantum state of a qubit register can be controlled only up to a finite precision, due to either fluctuating experimental parameters or to the uncontrolled interaction with the environment. Remarkably, this does not forbid the implementation of a quantum computer because errors can be corrected to some extent by redundantly encoding the information into “logical” qubits that consist of several “physical” qubits. In the recent years the control accuracy of few qubit registers progresses in a variety of physical systems : trapped ions, superconducting circuits, spins, … Several experiments have reported single-qubit-gate error rates below 0.1%, and two-qubit error rates below 1%, coming close to the “error rate threshold” of certain Quantum Error Correction (QEC) schemes. Experiments involving 10 to 50 qubits are planned for the near future.

In this context, many questions are pressing. On the experimental side: Are the experimental error rates really sufficient to implement QEC? What architecture can realistically reach the fault-tolerance level? On the theory side : Are there better QEC schemes less demanding in terms of physical qubits and gates overhead conceivable ? Are QEC schemes resilient to other error models than the simplistic ones? What is the “killer app” for a small-scale quantum computers with typically 50 physical qubits?

The goal of this workshop is to gather experts both on the theory and the experimental sides, and to address some of these issues.

More information, see dedicated website: https://raqc.sciencesconf.org/