Direct observation of quantum phonon fluctuations in a one dimensional Bose gas

Abstract

We report the first direct observation of collective quantum fluctuations in a continuous field. Shot-to-shot atom number fluctuations in small sub-volumes of a weakly interacting ultracold atomic 1D cloud are studied using \textit{in situ} absorption imaging and statistical analysis of the density profiles. In the cloud centers, well in the \textit{quantum quasicondensate} regime, the ratio of chemical potential to thermal energy is $\mu /k_{B}T\simeq 4$, and, owing to high resolution, up to 20% of the microscopically observed fluctuations are quantum phonons. Within a non-local analysis at variable observation length, we observe a clear deviation from a classical field prediction, which reveals the emergence of dominant quantum fluctuations at short length scales, as the thermodynamic limit breaks down.

4 pages, 3 figures (Supplementary material 3 pages, 3 figures)

References in corpus (5)

• Many-Body Physics with Ultracold Gases
• Extension of Bogoliubov theory to quasi-condensates
• Observation of Correlated Particle-Hole Pairs and String Order in Low-Dimensional Mott Insulators
• Observation of scale invariance and universality in two-dimensional Bose gases
• Effective mean-field equations for cigar-shaped and disk-shaped Bose-Einstein condensates

Cited by in corpus (28)

• Fermi gases in one dimension: From Bethe Ansatz to experiments
• Quantum transport in ultracold atoms
• Finite temperature correlations in the Lieb-Liniger 1D Bose gas
• The Planck distribution of phonons in a Bose-Einstein condensate
• Non-destructive selective probing of phononic excitations in a cold Bose gas using impurities
• Many-body processes in black and grey matter-wave solitons
• Hawking radiation correlations in Bose Einstein condensates using quantum field theory in curved space
• Correlation lengths of the repulsive one-dimensional Bose gas
• Excitations and number fluctuations in an elongated dipolar Bose-Einstein condensate
• Universal damping behavior of dipole oscillations of one-dimensional ultracold gases induced by quantum phase slips
• Classical field records of a quantum system: their internal consistency and accuracy
• Instability of the superfluid flow as black-hole lasing effect
• Critical phenomena in one dimension from a Bethe ansatz perspective
• Phase-induced transport in atomic gases: from superfluid to Mott insulator
• Universal local pair correlations of Lieb-Liniger bosons at quantum criticality
• Anisotropic Coherence properties in a trapped quasi2D dipolar gas
• Enhanced quantum spin fluctuations in a binary Bose-Einstein condensate
• Effective equations for matter-wave gap solitons in higher-order transversal states
• Classical fields in the one-dimensional Bose gas: applicability and determination of the optimal cutoff
• Number Fluctuations of a Dipolar Condensate: Anisotropy and Slow Approach to the Thermodynamic Regime
• Two-body correlations and natural orbital tomography in ultracold bosonic systems of definite parity
• Many-body density and coherence of trapped cold bosons
• Fluctuations of spinor Bose-Einstein condensates
• Mesoscopic density grains in the 1d interacting Bose gas from the exact Yang-Yang solution
• Accurate one-dimensional effective description of realistic matter-wave gap solitons
• Finite resolution fluctuation measurements of a trapped Bose-Einstein condensate
• Professor Chen Ping Yang's early significant contributions to mathematical physics
• Beyond-mean-field effects in Rabi-coupled two-component Bose-Einstein condensate