Low-Dimensional Quantum Gases on Atom Chips

Low-dimensional quantum systems show spectacular new features, properties and phases, not encountered in their 3D counterparts. Prominent examples are the quantum Hall effect in 2D electron gasses or the quantized resistance of 1D nano-wires. These phenomena at the same time stimulate fundamental research on confined quantum systems but also directly lead to industrial applications in precision magnetometry and nano-electronics. This proposal concerns the use of one-dimensional ultracold atomic quantum gases on atom chips to address unresolved fundamental questions of low-dimensional quantum systems, which are here encompassed by the three themes of Dimensionality, Integrability and Dynamics. The project will be carried out using a new experimental setup enabling investigations of bosons, fermions, and Bose-Fermi mixtures. The atom chip environment provides an ideal platform for accessing a wide range of parameters and regimes of one-dimensional gases. In the context of Dimensionality, the main goals of the project are to identify and characterize quantum degeneracy for dilute Bose and Fermi gases in the 3D-1D crossover regime and ascertain experimentally under which conditions quantum gases can be considered as one-dimensional. In the context of Integrability, the main goals of the project are to identify the breakdown of thermalisation in bosonic and fermionic 1D systems and answer the question, whether and how integrable systems reach a thermodynamic equilibrium state. In the context of Dynamics, the main goals of the project are to investigate the interplay of tunnelling and dimensionality in coupled one-dimensional Bose gases and the realisation of bright solitons in a Bose-Fermi mixture to ultimately observe controlled collision of two bright matter-wave solitons. The goal of this research is to establish one-dimensional atomic gases as general model systems and "quantum simulators" for other low-dimensional systems and develop new tools for their analysis. To this end, we aim at the development of the atomchip for low-dimensional systems as optical lattices have become for solid-state systems. In addition, by performing matter-wave interferometry over a large range of parameters we will ascertain the ideal geometry and configuration for applications to high-precision sensing and metrology. Furthermore, the realisation and characterisation of bright matter-wave solitons in a Bose-Fermi mixture could facilitate future experiments in such areas as soliton interferometry and soliton-surface interactions for the development of sensitive surface probes, which would, respectively, have ramifications for the fields of precision measurement and surface science.

Low-dimensional quantum systems show spectacular new features, properties and phases, not encountered in their 3D counterparts. Prominent examples are the quantum Hall effect in 2D electron gasses or the quantized resistance of 1D nano-wires. These phenomena at the same time stimulate fundamental research on confined quantum systems but also directly lead to industrial applications in precision magnetometry and nano-electronics. This proposal concerns the use of one-dimensional ultracold atomic quantum gases on atom chips to address unresolved fundamental questions of low-dimensional quantum systems, which are here encompassed by the three themes of Dimensionality, Integrability and Dynamics. The project will be carried out using a new experimental setup enabling investigations of bosons, fermions, and Bose-Fermi mixtures. The atom chip environment provides an ideal platform for accessing a wide range of parameters and regimes of one-dimensional gases. In the context of Dimensionality, the main goals of the project are to identify and characterize quantum degeneracy for dilute Bose and Fermi gases in the 3D-1D crossover regime and ascertain experimentally under which conditions quantum gases can be considered as one-dimensional. In the context of Integrability, the main goals of the project are to identify the breakdown of thermalisation in bosonic and fermionic 1D systems and answer the question, whether and how integrable systems reach a thermodynamic equilibrium state. In the context of Dynamics, the main goals of the project are to investigate the interplay of tunnelling and dimensionality in coupled one- dimensional Bose gases and the realisation of bright solitons in a Bose-Fermi mixture to ultimately observe controlled collision of two bright matter-wave solitons. The goal of this research is to establish one-dimensional atomic gases as general model systems and "quantum simulators" for other low-dimensional systems and develop new tools for their analysis. To this end, we aim at the development of the atomchip for low-dimensional systems as optical lattices have become for solid-state systems. In addition, by performing matter-wave interferometry over a large range of parameters we will ascertain the ideal geometry and configuration for applications to high-precision sensing and metrology. Furthermore, the realisation and characterisation of bright matter-wave solitons in a Bose-Fermi mixture could facilitate future experiments in such areas as soliton interferometry and soliton-surface interactions for the development of sensitive surface probes, which would, respectively, have ramifications for the fields of precision measurement and surface science.