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arXiv · 2105.10408

Single-particle versus many-body phase coherence in an interacting Fermi gas

Giovanni Pecci·Piero Naldesi·Anna Minguzzi·Luigi Amico
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Abstract

In quantum mechanics, each particle is described by a complex valued wave-function characterized by amplitude and phase. When many particles interact each other, cooperative phenomena give rise to a quantum many-body state with a specific quantum coherence. What is the interplay between single-particle's phase coherence and many-body quantum coherence? Over the years, such question has been object of profound analysis in quantum physics. Here, we demonstrate how the time-dependent interference formed by releasing an interacting degenerate Fermi gas from a specific matter-wave circuit in an effective magnetic field can tell apart the two notions. Single-particle phase coherence, indicated by the first-order correlator, and many-body quantum coherence, indicated by the density-density correlator, are displayed as distinct features of the interferogram. Single particle phase coherence produces spiral interference of the Fermi orbitals at intermediate times. Many-body quantum coherence emerges as long times interference. The interplay between single-particle coherence and many-body coherence is reflected in a stepwise dependence of the interference pattern on the effective magnetic field.

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Giovanni Pecci, Piero Naldesi, Anna Minguzzi, Luigi Amico. 2021-05-21. Single-particle versus many-body phase coherence in an interacting Fermi gas. https://doi.org/10.1088/2058-9565%2Faca712

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