Philipp Treutlein

Title

Atom Chips – a Quantum Laboratory on a Microchip

Abstract

Atom chips provide a versatile quantum laboratory for experiments with ultracold atomic gases. Electromagnetic fields from microstructured wires and electrodes are used to cool, trap, and coherently manipulate the quantum state of the atoms. This allows us to realize chip-based atomic clocks and interferometers, which combine high precision with a compact and robust setup. In such an interferometer, we generate spin-squeezed states of the atoms through the “one-axis twisting model” first described by Kitagawa and Ueda in 1993. These multi-particle entangled states are a useful resource for quantum metrology, as they allow one to overcome the standard quantum limit of interferometric measurement. Another intriguing possibility is to use the atoms as a sensitive probe for electromagnetic fields close to the chip surface. As an example, we use atoms to directly image microwave near-field distributions close to an integrated microwave circuit. A particularly exciting perspective of atom chip experiments is to build hybrid quantum systems in which the atoms interact coherently with on-chip solid-state systems such as micromechanical oscillators or superconducting devices.