We aim to widen the range of quantum simulations with cold atoms, by investigating phenomena arising from the long-ranged dipolar interaction in reduced dimensionalities. We are operating a new experimental setup based on quantum gases of the highly magnetic Dysprosium atoms. This is a joint project between LENS and CNR-INO, Sezione di Pisa.

Observation of two broken symmetries in a supersolid

The paradoxical supersolid phase of matter has the apparently incompatible properties of crystalline order and superfluidity. A crucial feature of a one-dimensional supersolid is the occurrence of two gapless excitations reflecting the Goldstone modes associated with the spontaneous breaking of two continuous symmetries: the breaking of phase invariance, corresponding to the locking of the phase of the atomic wave functions at the origin of superfluid phenomena, and the breaking of translational invariance due to the lattice structure of the system. We demonstrate the supersolid nature of the coherent stripe regime we discovered in dipolar Bose-Einstein condensates. In our trapped system, the symmetry breaking appears as two distinct compressional oscillation modes, reflecting the gapless Goldstone excitations of the homogeneous system. We observe that the two modes have different natures, with the higher frequency mode associated with an oscillation of the periodicity of the emergent lattice and the lower one characterizing the superfluid oscillations. Our work paves the way to explore the two quantum phase transitions between the superfluid, supersolid and crystal-like configurations that can be accessed by tuning a single interaction parameter.

L. Tanzi, et al.
Supersolid symmetry breaking from compressional oscillations in a dipolar quantum gas
Nature 574, 382 (2019)

See also the Nature News and Views by S. M. Mossman:

S. M. Mossman, Sounds of a supersolid detected in dipolar atomic gases for the first time
Nature 574, 341 (2019)

and the Nature Physics research highligh by Y. Li:

Y. Li, The buried trace
Nature Physics 15, 986 (2019)

Dy People

Giulio Biagioni
Master student
Juliàn Gabriel Maloberti
Master student
Luca Tanzi
Scientific staff
Andrea Fioretti
Scientific staff
Carlo Gabbanini
Scientific staff
Giovanni Modugno
Scientific staff
Former members and collaborators:
Jacopo Catani
Silvia Gozzini
Massimo Inguscio
Eleonora Lucioni

Dy contacts

For further information, request of material, job opportunities, please contact:

Giovanni Modugno
(modugno@lens.unifi.it)

Dy funding