Erbium Project:

Exploring exotic magnetic quantum gases


Institut für Experimentalphysik,
University of Innsbruck, and
Austrian Academy of Sciences,
Innsbruck, Austria

Content: News / Research / Experimental Setup and Status / Why Erbium? / Erbium Team


News from the Lab

See our new group website for more informations!


The project is dedicated to the exploration of ultracold erbium (Er) atoms as a new and exotic species for research on ultracold quantum gases and strongly correlated quantum systems.

Our main project goals are:

The Experimental Setup and Status

We are in the process building our experimental apparatus.

As a rare-earth atom, Er has a complex energy level structure and, at a first glance, seems not be suited for laser cooling experiments. Nevertheless, the group of J. J. McClelland at NIST (Gaithersburg) has demonstrated the possibility of efficient laser cooling of Er atoms [H. Y. Ban, J. J. McClelland].
Five different transitions from the ground state are promising for laser cooling, corresponding to a wavelength of 401, 583, 631, 841, and 1299 nm. Erbium is thus extraordinarily rich for the application of different laser cooling schemes.


Energy levels of erbium for different angular momentum quantum numbers J [1].
States with odd/even parity are indicated by black/red horizontal lines
The different laser cooling transition lines are indicated by arrows.


To produce an Er BEC we will start with a Zeeman-slowed atomic beam using the strong 401-nm line. The atomic beam will then be captured into a MOT operating on the weaker 583-nm line. Optionally, this will be followed by further laser cooling stages, like Raman sideband cooling schemes. Finally the atoms will be loaded into an optical dipole trap formed by far-detuned laser light.

Why Erbium?

Erbium offers a unique combination of properties, not found in any other species used for quantum gas experiments.

  • Several stable isotopes: Among the five bosonic isotopes there are three abundant ones (>15%), well suited for trapping a large number of atoms. The fermionic isotope167Er is remarkably abundant as compared to other fermionic systems. This richness in isotopes will also lead to a corresponding richness in the scattering properties, regarding the sign and magnitude of the background scattering lengths and the character of Feshbach resonances.

  • Large atomic mass: Many relevant energies in the system, such as the recoil energy and the mean field energy will be reduced by the large mass of Er. As a heavy atom, erbium is expected to show very rich interactions properties. The collisional physics will be, for instance, enriched by strong spin-orbit contributions and a large orbital angular momentum (L=5) in the ground state, which provides a scenario never considered in ultracold collisional physics.

  • Strong magnetic character: Between the laser-cooled species, erbium has one of the strongest magnetic moment with µ = 7µB. Simple arguments, based on large Zeeman shifts and strong spin-orbit interactions, let us expect the appearance of many Feshbach resonances in a relatively narrow magnetic field range. The large magnetic moment in combination with the large mass leads to a particularly strong dipolar character.

The Team

The Er team is working at the Institut für Experimentalphysik, University of Innsbruck, Austria.


From left to right: Michael Springer, Michael Mark, Kiyotaka Aikawa, Alexander Rietzler, Francesca Ferlaino, Albert Frisch, Rudi Grimm, Simon Baier

Er Team Sledging

From left to right: Simon Baier, Albert Frisch, Erik Zupanic, Michael Mark, Michael Springer, Kiyotaka Aikawa
In front: Francesca Ferlaino


Present Members:

  • Simon Baier (PhD Student)
  • Daniel Petter (Master Student), not in picture
  • Lauriane Chomaz (PostDoc), not in picture
  • Manfred J. Mark (Senior Scientist), not in picture
  • Rudolf Grimm
  • Francesca Ferlaino (PI)

Visiting Scientist:

  • Erik Zupanic, Oct. 2011 - Jan. 2012

Former Members:

  • Albert Frisch (PostDoc)
  • Kiyotaka Aikawa (Postdoc)
  • Michael Mark (Postdoc)
  • Michael Springer (Master Student)
  • Julien Cividini
  • Johannes Schindler (Master Student)
  • Alexander Rietzler (Master Student)

More Pictures

TEAM, May 2011 TEAM, Jan 2011 TEAM, Apr 2010
Open positions:

We have open positions for diploma/master- and PhD-students

Contact Francesca Ferlaino for further information



last change: 27-07-2015 by MJM