Missions

Quantum mechanics is the fundamental theory that rules the way nature works at the microscopic scale. However, a fully quantum description is often a fierce challenge, both for analytical developments and numerical calculations, especially for objects containing hundreds or thousands of particles. In those cases, it may be convenient to separate the system into several subsystems, some of which are treated classically and some quantum mechanically.
Here, we will address this problem from two complementary perspectives. On the one hand the Wigner representation casts quantum mechanics in the classical formalism of probability distributions evolving in the phase space. On the other, the Koopman-von Neumann theory is a representation of classical mechanics that uses a mathematical formalism identical to that of quantum mechanics (operators in Hilbert spaces). These two approaches appear to be ideal candidates to describe hybrid systems in which some variables are classical and others are quantum.

Activités

Two practical applications are envisaged: (i) The entanglement of two distant quantum spin qubits coupled via magnetic dipole interactions mediated by a classical system, such as a macroscopic ferromagnet, magnonic excitations, or magnetic domain walls; (ii) The effect of strong spin-orbit coupling on the electronic and spin transport in one-dimensional semiconductor quantum wires. For both cases, we will address several effects that are crucial for any quantum computing scenario, such as the loss of spin coherence through coupling to a classical system, or the efficiency of classically-mediated qubit entanglement.

Compétences

We are looking for a highly motivated candidate with a PhD degree in theoretical/computational physics or applied mathematics. A strong background in quantum mechanics and computer simulations is required (e.g., Python, Mathematica, Matlab). Some knowledge of nonequilibrium statistical mechanics (Boltzmann and Vlasov equations) and magnetism (spin dynamics, Landau-Lifshitz-Gilbert equation) is desirable. Proficiency in English is also required (minimum B2 level referring to the european framework of reference for language).

Contexte de travail

The successful candidate will join the Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS-UMR 7504) CNRS - Université de Strasbourg, more specifically the team Quantum dynamics of nano-objects (https://tinyurl.com/QDyno-ipcms), within the Département Ultrafast Optics and Nanophotonics (DON). He or she will take part in the team's monthly group meetings as well as the presentation and discussion meetings with our UK partner planned as part of this collaborative project. Short secondments to the School of Mathematics and Physics of the University of Surrey (UK) are envisaged.

Le poste se situe dans un secteur relevant de la protection du potentiel scientifique et technique (PPST), et nécessite donc, conformément à la réglementation, que votre arrivée soit autorisée par l'autorité compétente du MESR.

Informations complémentaires

This project is funded by the graduate school “Quantum Science and Nanomaterials” (QMat), https://qmat.unistra.fr/.
Applicants should send a detailed CV (with names and email addresses of Master and PhD supervisors, and possibly other references), official Master grade transcripts, list of publications, and a letter of motivation.