Periodic Reporting for period 4 - ANYON (Engineering and exploring anyonic quantum gases)
Période du rapport: 2023-07-01 au 2024-12-31
In the project ANYON we are working towards the realization of topological fractional quantum Hall states such as the Laughlin state and their anyonic excitations in experiments with ultracold atoms.
Such a realization in a well-controlled artificial quantum system with single-particle resolved imaging will allow for new insight into the intriguing strongly correlated states, which still pose open questions, and it might allow for the first direct observation of anyonic exchange statistics by manipulating the anyonic excitations. This is important both for establishing anyons as profoundly different particles beyond the dichotomy of bosons and fermions, which described all fundamental particles, and for working towards a control of these particles, which might be used as topological qubit in future quantum computing. The impact of quantum computing on society is based on its promise of improved solving of important optimization problems and as energy-efficient alternative to supercomputers.
During the course of the project, we have made important steps towards these goals both via experimental progress and by teaming up with theory groups to identify the most suitable approaches. We have introduced novel microscopy techniques, which will be important for deeper insights into ultracold atom systems and used them for studying the topological BKT phase.
Such a realization in a well-controlled artificial quantum system with single-particle resolved imaging will allow for new insight into the intriguing strongly correlated states, which still pose open questions, and it might allow for the first direct observation of anyonic exchange statistics by manipulating the anyonic excitations. This is important both for establishing anyons as profoundly different particles beyond the dichotomy of bosons and fermions, which described all fundamental particles, and for working towards a control of these particles, which might be used as topological qubit in future quantum computing. The impact of quantum computing on society is based on its promise of improved solving of important optimization problems and as energy-efficient alternative to supercomputers.
During the course of the project, we have made important steps towards these goals both via experimental progress and by teaming up with theory groups to identify the most suitable approaches. We have introduced novel microscopy techniques, which will be important for deeper insights into ultracold atom systems and used them for studying the topological BKT phase.
The experimental realization of fractional quantum Hall states requires advanced methods both for providing the microscopic access to all particles of the quantum many-body system and for creating the artificial magnetic field that gives rise to these correlated states. The project ANYON has made important progress in these two issues.
Firstly, we have teamed up with another experimental group of our institute to develop a new microscopy technique, which we call quantum gas magnifier, and which is based on matter-wave magnification of the system before the optical imaging. This approach removes issues of depth of focus and of optical density and allows imaging three-dimensional systems with sub-lattice-resolution. By combining it with free-space fluorescence imaging for single-atom sensitivity, we will in the future use this method for imaging the fractional quantum Hall states and extract all relevant correlation functions. Furthermore, we have introduced a phase microscope, which allows to measure phases instead of densities with very high resolution, and employed it for studying the phase coherence in the topological BKT phase.
Secondly, we have worked towards the realization of artificial magnetic fields via a rotation of the trap making use of the formal equivalence of centrifugal and Lorentz force. We have produced such traps with high quality as optical tweezers shaped via digital mirror devices.
We have also teamed up with a theory group from ICFO to study the adiabatic preparation of the relevant states by appropriate sweeps of the trap rotation frequency and anisotropy and found protocols, which allow a tenfold speedup of the preparation time, making it easier to compete with heating from technical noise sources.
We have disseminated the results via presentations at many international conferences and workshops.
Firstly, we have teamed up with another experimental group of our institute to develop a new microscopy technique, which we call quantum gas magnifier, and which is based on matter-wave magnification of the system before the optical imaging. This approach removes issues of depth of focus and of optical density and allows imaging three-dimensional systems with sub-lattice-resolution. By combining it with free-space fluorescence imaging for single-atom sensitivity, we will in the future use this method for imaging the fractional quantum Hall states and extract all relevant correlation functions. Furthermore, we have introduced a phase microscope, which allows to measure phases instead of densities with very high resolution, and employed it for studying the phase coherence in the topological BKT phase.
Secondly, we have worked towards the realization of artificial magnetic fields via a rotation of the trap making use of the formal equivalence of centrifugal and Lorentz force. We have produced such traps with high quality as optical tweezers shaped via digital mirror devices.
We have also teamed up with a theory group from ICFO to study the adiabatic preparation of the relevant states by appropriate sweeps of the trap rotation frequency and anisotropy and found protocols, which allow a tenfold speedup of the preparation time, making it easier to compete with heating from technical noise sources.
We have disseminated the results via presentations at many international conferences and workshops.
With the results discussed above, the project has made significant progress beyond the state of the art and has laid the ground for realizing fractional quantum Hall states with ultracold atoms. The novel techniques of the quantum gas magnifier and the phase microscope are important breakthroughs that will significantly advance the field of cold atoms. The magnifier allows accessing novel regimes such as three-dimensional systems and sub-wavelength optical lattices. The phase microscope allows measuring phases at the ultimate level of individual lattice sites and therefore opens microscopy to new observables beyond occupations or densities with important implications also for strongly-correlated systems.