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.

The competition of dipole-dipole and contact interactions leads to exciting new physics in dipolar gases, well-illustrated by the recent observation of quantum droplets and rotons in dipolar condensates. We have now discovered that the combination of the roton instability and quantum stabilization leads under proper conditions to a novel regime that presents supersolid properties, due to the coexistence of periodic density modulation and phase coherence. In a combined experimental and theoretical analysis (with the University of Hannover), we have determined the parameter regime for the formation of coherent stripes, whose lifetime of a few tens of milliseconds is limited by the eventual destruction of the stripe pattern due to three-body losses. Our results open intriguing prospects for the development of long-lived dipolar supersolids.

L. Tanzi et al.
Observation of a dipolar quantum gas with metastable supersolid properties
Phys. Rev. Lett. 122, 130405 (2019)

We have characterized the scattering properties of ultracold 162Dy atoms for magnetic fields between 6 and 30 G. In addition to the typical chaotic distribution of narrow Feshbach resonances in Lanthanides, we have discovered two rather isolated broad features. A characterization using the complementary measurements of losses, thermalization, anisotropic expansion and molecular binding energy points towards resonances of predominant s-wave character, with dimensionless strength s=0.5(3). Such resonances will ease the investigation of quantum phenomena relying on the interplay between dipole and contact interactions.

E. Lucioni, et al.
Dysprosium dipolar Bose-Einstein condensate with broad Feshbach resonances
Phys. Rev. A 97, 06060701(R) (2018)

We observed the transition to BEC for 162Dy atoms!
Our dipolar BECs are made up at the moment by up to 3⨯104 atoms. Atoms from the MOT are transferred into an in-vacuum optical resonator where we perform a first evaporation down to a few μK. Afterwards, we load the atoms in a crossed optical trap and condensation temperature is reached by evaporation ramps. The atomic dipoles are aligned along the vertical direction by an uniform magnetic field of a few Gauss and the vertical trapping frequency is higher than the horizontal ones to prevent dipolar collapse. The transition temperature for our trapping potential is below 100 nK.

We realize a magneto-optical trap for 162Dy atoms on the intermediate linewidth transition at 626 nm. We trap over 2✕108 atoms at temperatures as low as 20 μK in 5 seconds. We observe the best loading at large detuning, -35Γ. Under these operating conditions, MOT forms below the quadrupole centre and the MOT light acts as optical pumping as well.

E. Lucioni et al.
A new setup for experiments with ultracold Dysprosium atoms
Eur. Phys. J. Spec. Top. 226, 2775 (2017)

We finished assembling the vacuum setup. In the final cell, we included a passive high finesse optical resonator to transfer a large volume of atoms from the MOT to an optical trap that requires low power.

Light at 421nm will be employed for transverse cooling and for the Zeeman slower. Up to 1.2W of blue light is produced in a homemade frequency doubling cavity and is locked to the atomic line using saturated absorption spectroscopy in a hollow cathode lamp.

Light at 626nm will be employed for the magneto-optical trap (MOT). The red light is obtained from a commercial laser system and is locked to the atomic line using saturated absorption spectroscopy in a iodine cell.

Dy People

Francesca Famà
Master student
Alessandro Fregosi
Master student
Eleonora Lucioni
Research fellow
Luca Tanzi
Research fellow
Jacopo Catani
Permanent researcher
Silvia Gozzini
Permanent researcher
Massimo Inguscio
Permanent researcher
Andrea Fioretti
Permanent researcher
Carlo Gabbanini
Permanent researcher
Giovanni Modugno
Permanent researcher

Dy contacts

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

Giovanni Modugno
(modugno@lens.unifi.it)

Dy funding