This behavior, revealed for the first time, has been observed by employing an ultracold sample of Yb atoms, cooled at temperatures close to the absolute zero (100 nK), where the number of internal states (spin) could be artificially controlled and increased up to six, rather than being limited by Nature to 2 (as in case of electrons).
Under this light, the system has no direct analogue in “natural” systems (eg. solid state systems, where the number of electronic spin components is 2, or in nuclear systems, where the nucleons consituents (quarks) show 3 different natural “colours”).@
Among the results, it has been shown that such an increase of spin components in fermions (one of the two main classes of particles in which the consituents of the Universe can be divided into) leads to a “less fermionc” behavior, pushing the particles towards a “bosonic” one.@
This results have a transversal relevance, and show fundamental interest (long standing solid state theories, such as the Luttinger model for interacting electrons, can be tested), providing at the same time valuable experimental
information not yet satisfactorily described by present theories.@
The versatility of this system allows the realization of an effective “quantum simulator”, capable of validating predictions of forecoming theories belonging to a wealth of research areas, ranging from solid state to subnuclear physics.@
These results have been obtained at LENS laboratories from a collaboration among INO-CNR and University of Firenze (Physics Dept.), and recently appeared on Nature Physics (“A one-dimensional liquid of fermions with tunable spin”, doi:10.1038/nphys2878).
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