PhD Postion : Theory of localization effects in dynamics of mass-imbalanced quantum gas mixtures

COFUND QuanG; France; Sur place; EUR 20 000 - 23 000; Plein temps

Résumé du poste

COFUND QuanG invites applications for a First Stage Researcher (R1) PhD position in physics, funded under the Horizon Europe – COFUND program. The project studies many-body localization in quantum gas mixtures, with collaboration with LENS (Florence) and LPTMS (Saclay).

The three-year PhD is fully funded and starts 1 February 2027, pending grant approval. Applicants should hold a Master’s degree by the deadline of 7 September 2026, and must comply with MSCA mobility rules.

Qualifications

• Master’s degree or equivalent by the application deadline.
• Must not already hold a doctoral degree.
• MSCA mobility rule: must not have resided or carried out main activity in France for more than 12 months in the 36 months preceding the deadline.

Connaissances

Theoretical physics

Scientific programming

Condensed-matter physics

Communication skills

Teamwork

Formation

Master's degree

Description du poste

Organisation/Company COFUND QuanG Research Field Physics Researcher Profile First Stage Researcher (R1) Positions PhD Positions Application Deadline 7 Sep 2026 - 12:00 (Europe/Paris) Country France Type of Contract Temporary Job Status Full-time Offer Starting Date 1 Feb 2027 Is the job funded through the EU Research Framework Programme? Horizon Europe – COFUND Reference Number 101261699 Is the Job related to staff position within a Research Infrastructure? No

Offer Description

General Scope:
When a classical atomic gas is driven out of the thermal equilibrium by, for example, locally modifying its temperature or density, the subsequent dynamic evolution (i.e., collisions between atoms) brings it back to the equilibrium state, in which the memory about the initial perturbation is completely erased. The situation is much more complex in a quantum gas where atoms obey Schrödinger equation and where interference effects become important. There are indications that thermalization may not always take place despite collisions between atoms and that the gas may retain memory about the perturbation even for infinitely long times. This phenomenon is known as “many-body localization” (MBL) and its theoretical understanding is notoriously difficult due to the exponential scaling of Hilbert space dimensionality with the number of atoms. Understanding MBL is crucial for correctly describing electric transport in metals and superconductors as well as for proper design of the future quantum computers. A particular system in which MBL may be expected is a mixture of two different quantum gases with a large mass ratio M/m, implying well separated time scales for the dynamics of the two components in the absence of interaction between them. As a result, a time interval exists during which heavy atoms (mass M) can be assumed almost immobile whereas light atoms (mass m

PhD Subject:
This theoretical thesis project is motivated by experiments conducted by Matteo Zaccanti and his colleagues at European Laboratory for Non-Linear Spectroscopy (LENS) in Florence, Italy. In the experiment, one observes the expansion of a small cloud of light fermionic atoms (6Li) released inside a large, three-dimensional sample of heavy fermionic atoms (53Cr). Experimental observations and their initial theoretical analysis suggest significant localization effects, but the analysis is complicated by several aspects that are not included in the existing theoretical model: wide distribution of light atoms in energy, leading to qualitatively different behaviors of different spectral components; slow but not fully negligible motion of heavy atoms during the experiment; fermionic statistics of both atomic species, implying nontrivial correlations in their spatial arrangements; etc. We plan to overcome these complications using two different but
complementary theoretical approaches. The first one implies solving the time-dependent Schrödinger equation for the wave function of light atoms, assuming scattering by immobile or slowly moving heavy atoms at random but correlated positions. Probability distributions of measurable quantities can them be predicted by the Monte-Carlo method. In this approach, the energy dependence of interference effects, motion of heavy atoms, and correlations in their positions can be taken into account explicitly at the price of high (but affordable) computational cost. The second approach is based on the self-consistent theory of localization that allows for calculating average quantities directly, without explicit averaging over random realizations of heavy-atom positions. Less microscopic than the first approach, the self-consistent theory allows for a better understanding of underlying physics. Its power in describing localization experiments has been already demonstrated in acoustics and optics. The results of both approaches will be compared with experimental data, allowing for advancing our understanding of fermionic mixture dynamics. If time allows, a generalization to bosonic mixtures will be attempted.
This project involves a collaboration with Matteo Zaccanti (LENS, Florence) and Dmitry Petrov (LPTMS, Saclay).

Required Skills

• Knowledge and ability to use methods of theoretical physics
• Some experience in scientific programming
• Basics of condensed-matter, cold-atom, and wave physics
• Communication skills
• Ability to work in a team

Applicants must hold a Master’s degree or an equivalent qualification by the application deadline and must not already hold a doctoral degree. Applicants must also comply with the MSCA mobility rule: they must not have resided or carried out their main activity (work, studies, etc.) in France for more than 12 months during the 36 months immediately preceding the application deadline. Applicants must not be current employees of the host laboratory. There are no nationality or age restrictions.

Additional comments

About the QuanG2 PhD Call

This PhD position is offered as part of the QuanG2 PhD Call for Applications, a doctoral programme coordinated by Université Grenoble Alpes and dedicated to training the next generation of researchers in quantum science and technology. The programme offers fully funded three-year PhD positions within the Grenoble quantum research ecosystem, providing doctoral candidates with a high-level international research environment and dedicated funding for their research and training activities.

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