Research Timour Ichmoukhamedov

Abstract

During the last two decades, Machine Learning (ML) and Artificial Intelligence (AI) tools have created a true paradigm shift and impacted numerous fields and industries. In quantum physics, ML is rapidly gaining popularity and is already being extensively used for variational quantum state representation. Recently, a more ambitious and new research direction is developing where Reinforcement Learning agents could be used to solve quantum statistical problems while improving during the task. This field is still in its infancy and is highly promising to yield efficient and scalable computational tools for physics that would be situated between semi-analytical approximations and brute-force Monte Carlo calculations. In this proposal such tools will be developed for applications in modern quantum many-body physics at finite temperatures. In particular, the goal is to train smart AI agents to sample path integrals that occur in various quantum statistical problems. Important research questions include exploring domain generalization where learned knowledge by the agent can be transferred between tasks. The developed methodology will be applied to challenging systems in condensed matter physics such as many fermion systems and polaronic systems with memory. Besides providing powerful computational tools, this research on the thrilling synthesis of Reinforcement Learning and quantum statistics will yield new insights and perspectives at the forefront of the current AI explosion in physics.

Researcher(s)

• Promoter: Tempere Jacques
• Fellow: Ichmoukhamedov Timour

Research team(s)

• Theory of quantum systems and complex systems

Project type(s)

• Research Project

Abstract

A Bose-Einstein condensate (BEC) can be thought of as a gas of atoms which undergoes a transition into a specific phase at very low temperatures. In this new phase the atomic gas exhibits various peculiar properties such as superfluidity, quantized vortices and many other phenomena not expected in normal gases. One such interesting problem is that of an impurity (usually an atom of a different species) moving through a BEC. This impurity will disturb the gas around it and create a dip of lower density which it will have to drag along. This will modify the properties of the impurity and for example change the effective mass, analogous to a person having more trouble walking on a trampoline and dragging along the deformation in the fabric. Such an impurity together with the dip in density as a whole is called a Bose-polaron. In 2016 two experiments first realized condensates that contained many Bose-polarons and gave rise to an active discussion in the theoretical community. It has been shown that for an accurate theoretical description of the polaron additional correction terms had to be taken into account which were not present in previous discussions. This has been recently done for a description of single Bose-polarons. In this research these correction terms will be included to describe a system of many polarons which in combination has not been done before. The results found here will also be extended to other atomic gases called ultracold fermionic gases.

Researcher(s)

• Promoter: Tempere Jacques
• Fellow: Ichmoukhamedov Timour

Research team(s)

• Theory of quantum systems and complex systems

Project type(s)

• Research Project

Abstract

A Bose-Einstein condensate (BEC) can be thought of as a gas of atoms which undergoes a transition into a specific phase at very low temperatures. In this new phase the atomic gas exhibits various peculiar properties such as superfluidity, quantized vortices and many other phenomena not expected in normal gases. One such interesting problem is that of an impurity (usually an atom of a different species) moving through a BEC. This impurity will disturb the gas around it and create a dip of lower density which it will have to drag along. This will modify the properties of the impurity and for example change the effective mass, analogous to a person having more trouble walking on a trampoline and dragging along the deformation in the fabric. Such an impurity together with the dip in density as a whole is called a Bose-polaron. In 2016 two experiments first realized condensates that contained many Bose-polarons and gave rise to an active discussion in the theoretical community. It has been shown that for an accurate theoretical description of the polaron additional correction terms had to be taken into account which were not present in previous discussions. This has been recently done for a description of single Bose-polarons. In this research these correction terms will be included to describe a system of many polarons which in combination has not been done before. The results found here will also be extended to other atomic gases called ultracold fermionic gases.

Researcher(s)

• Promoter: Tempere Jacques
• Fellow: Ichmoukhamedov Timour

Research team(s)

• Theory of quantum systems and complex systems

Project type(s)

• Research Project