A Quantum Scattering Interferometer

Abstract

The collision of two ultra-cold atoms results in a quantum-mechanical superposition of two outcomes: each atom continues without scattering and each atom scatters as a spherically outgoing wave with an s-wave phase shift. The magnitude of the s-wave phase shift depends very sensitively on the interaction between the atoms. Quantum scattering and the underlying phase shifts are vitally important in many areas of contemporary atomic physics, including Bose-Einstein condensates, degenerate Fermi gases, frequency shifts in atomic clocks, and magnetically-tuned Feshbach resonances. Precise measurements of quantum scattering phase shifts have not been possible until now because, in scattering experiments, the number of scattered atoms depends on the s-wave phase shifts as well as the atomic density, which cannot be measured precisely. Here we demonstrate a fundamentally new type of scattering experiment that interferometrically detects the quantum scattering phase shifts of individual atoms. By performing an atomic clock measurement using only the scattered part of each atom, we directly and precisely measure the difference of the s-wave phase shifts for the two clock states in a density independent manner. Our method will give the most direct and precise measurements of ultracold atom-atom interactions and will place stringent limits on the time variations of fundamental constants.

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References in corpus (11)

• Formation and Propagation of Matter Wave Soliton Trains
• Formation of a Matter-Wave Bright Soliton
• Spin domains in ground state spinor Bose-Einstein condensates
• Observation of a Strongly-Interacting Degenerate Fermi Gas of Atoms
• The dynamics of component separation in a binary mixture of Bose-Einstein condensates
• Radio-Frequency Spectroscopy of Ultracold Fermions
• Resolved-sideband Raman cooling to the ground state of an optical lattice
• Precision measurement of spin-dependent interaction strengths for spin-1 and spin-2 87Rb atoms
• Interferometric determination of the s- and d-wave scattering amplitudes in ${}^{87}$Rb
• Imaging of s and d partial-wave interference in quantum scattering of identical bosonic atoms
• Enhancement of variation of fundamental constants in ultracold atom and molecule systems near Feshbach resonances

Cited by in corpus (14)

• Mesoscopic atomic entanglement for precision measurements beyond the standard quantum limit
• Progress in Atomic Fountains at LNE-SYRTE
• Composite pulses for interferometry in a thermal cold atom cloud
• Decoherence and Collisional Frequency Shifts of Trapped Bosons and Fermions
• Scattering of Cold Atom Coherences by Hot Atoms: Frequency Shifts from Background Gas Collisions
• Avoided crossings between bound states of ultracold Cesium dimers
• Interference of interacting matter waves
• Feshbach resonances in Cesium at Ultra-low Static Magnetic Fields
• Sensitivity to alpha-variation in ultracold atomic-scattering experiments
• Direct Observation of Resonant Scattering Phase Shifts and their Energy Dependence
• Atomic Clock Measurements of Quantum Scattering Phase Shifts Spanning Feshbach Resonances at Ultralow Fields
• Universal behaviour of diatomic halo states and the mass sensitivity of their properties
• Quantum Scattering in an Optical Collider for Ultracold Atoms
• Observation of Fermi acceleration with cold atoms