CSMP Seminar @ICTP Tuesday 27 September at 14:00 hrs - L.Stasi Seminar Room - Patrizia Vignolo

[Condensed Matter Section]

Condensed Matter and Statistical Physics Seminar
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Tuesday 27 September at 14:00 hrs.
Luigi Stasi Seminar Room, first floor Leonardo building


Patrizia VIGNOLO
INLN, Inst. Non-Lineaire de Nice, Valbonne, France

'Momentum Distribution and Symmetry Characterization of
One-Dimensional Strongly Interacting Fermi Gases'

Abstract:
One dimensional (1D) strongly correlated quantum systems are nowadays 
the subject of intense theoretical and experimental activity due to the 
incredible experimental control offered by ultra-cold atoms setups. In 
such systems, the momentum distribution is a powerful probe of both gas 
statistics and of the intertwined effect of interactions between 
particles and the effective dimensionality they move in.
A remarkable momentum distribution feature, in all dimensions, is the 
presence of universal power-law tails n(k)~k^{-4} for a gas where 
interactions can be schematized as contact ones (as it is the case for 
most standard cold gases experiments). The weight of such tails, denoted 
as Tan's contact, can be put into relation with several many-body 
quantities, ranging from the interaction energy to the depletion rate by 
inelastic collisions. In this work, we show that such tails also encode 
precious information about the permutational symmetry hiding behind the 
formation of magnetic-like structures in strongly-interacting 
multi-component Fermi gases.

More in details, we combine an exact solution at infinite interactions 
and numerical Matrix-Product-State (MPS) simulations at finite 
interactions, in order to predict the behavior of the momentum 
distribution tails for a mixture of k fermionic components under 1D 
harmonic confinement and interacting among each other with completely 
SU(k)-symmetric repulsive contact interactions.
We show that both the ground and excited states of the system have a 
well defined symmetry, thus indicating magnetic-like properties of the 
mixture, and that such information is fully encoded in the Tan's contact.