ERBIUM LAB

Erbium has very special properties that make it unique: a remarkably strong magnetic moment, many valence electrons, clock transitions, and an exceptionally rich internal atomic structure. In the ERBIUM LAB we bring all these properties in the quantum regime together to study strongly dipolar gases both in the continuum and in optical lattices

Our experiments have focused on studying the impact of dipolar interactions in various scenarios. In bulk systems, we have provided the first evidence of the many-body nature of these interactions and of their interplay with the Pauli exclusion principle, through the observation of the deformation of the Fermi surface [1]. At the microscopic scale, we focused on the intriguing chaotic scattering behavior of Er atoms, arising from the interplay between the orbital and magnetic anisotropies of the particles [2]. In lattices, we achieved a significant milestone by being the first to realize the extended Bose-Hubbard model, revealing the modified transition from a superfluid to a Mott insulator driven by dipolar interactions [3].

These explorations have led to an in-depth study of supersolidity, made possible by two fundamental experimental achievements. The observation of the transition from the ground state of an Er Bose-Einstein condensate to a self-sustaining macro-droplet state, demonstrated the unexpected stabilizing effect of quantum fluctuations [4]. Furthermore, the pioneering observation of roton-like quasiparticles revealed the possibility of inducing crystallization of the system via dipolar interactions [5]. These efforts have culminated in the long-awaited production of a long-lived supersolid, characterized by complex behavior reminiscent of both a crystal and a superfluid, as part of a collaboration between the Er-Dy and ERBIUM teams and our theoretical collaborators at IQOQI [6].

Remarkably, Er also features a large spin, offering many opportunities for quantum simulation. The groundwork has been laid with the implementation of a long-range Heisenberg XXZ model in a fermion lattice and the precise control of spin-exchange dynamics [7]. These efforts have been further enhanced by the recent demonstration of the manipulation of a narrow inner-shell orbital transition at 1299-nm [8], enabling exhaustive control over the spin composition of the system. This convergence of advancements holds the potential for the realization of a new generation of synthetic quantum magnets in clean, isolated, and fully controllable environments. The technological applications of such systems span a wide range, from precision sensing to quantum information processing.

[1] For a general overview of Fermi surface deformation, see our writeup. This work was published in Science, and the preprint can be found on the arXiv.

[2] For a general overview of this work on quantum chaos, see the following article on ScienceDaily. This work was published in Nature, and the preprint can be found on the arXiv.

[3] For a general overview of this work on the Bose-Hubbard model, see the press release by UIBK. This work was published in Science, and the preprint can be found on the arXiv.

[4] For a general overview of the BEC macrodroplet, see our writeup and the article by Physics Magazine. This work was published in Physical Review X, and the preprint can be found on the arXiv.

[5] For a general overview of the roton in Erbium, see our writeup, the press release by UIBK and . This work was published in Nature, and the preprint can be found on the arXiv.

[6] For a general overview of the supersolid phase, see our writeup and the press release by UIBK, and the article by Physics Magazine. This work was published in Physical Review X, and the preprint can be found on the arXiv.

[7] For a general overview of these lattice-confined dipolar fermions, see our writeup. This work was published in Physical Review Research, and the preprint can be found on the arXiv.

[8] For a general overview of this narrow inner-shell orbital transition, see our writeup. This work was published in Physical Review Research, and the preprint can be found on the arXiv.

A full list of the ERBIUM Lab publications can be found here.

Interested in joining us? Check out our open positions here.

Lab news

Observation of Fermi surface deformation in a dipolar quantum gas

Now in Science! In the presence of isotropic interactions, the Fermi surface of an ultracold Fermi gas is spherical. Introducing anisotropic interactions can deform it. This effect is subtle and challenging to observe experimentally. We report the observation of such a Fermi surface deformation in a degenerate dipolar Fermi gas of

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Quantum Chaos in Ultracold Collisions of Erbium

We have studied the scattering behavior of ultracold Er atoms and observed an enormous number of Fano-Feshbach scattering resonances and demonstrate high correlation in the spectra, underlying chaotic scattering between the particles. This work, now published in NATURE, is a joint effort between our group, John L. Bohn from JILA (Boulder,

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Reaching Fermi Degeneracy via Universal Dipolar Scattering

We report on the creation of the first degenerate dipolar Fermi gas of erbium atoms. We force evaporative cooling in a fully spin-polarized sample down to temperatures as low as 0.2 times the Fermi temperature. The strong magnetic dipole-dipole interaction enables elastic collisions between identical fermions even in the zero-energy

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Hyperfine structure of laser-cooling transitions in fermionic erbium-167

We have measured and analyzed the hyperfine structure of two lines, one at 583 nm and one at 401 nm, of the only stable fermionic isotope of atomic erbium as well as determined its isotope shift relative to the four most-abundant bosonic isotopes. Our work focuses on the J→J+1 laser

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Narrow-line magneto-optical trap for erbium

We report on the experimental realization of a robust and efficient magneto-optical trap for erbium atoms, based on a narrow cooling transition at 583 nm. We observe up to N=2×10^8 atoms at a temperature of about T=15 μK. This simple scheme provides better starting conditions for direct loading of dipole

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Bose-Einstein Condensation of Erbium

We report on the achievement of Bose-Einstein condensation of erbium atoms and on the observation of magnetic Feshbach resonances at low magnetic fields. By means of evaporative cooling in an optical dipole trap, we produce pure condensates of Er168, containing up to 7×104 atoms. Feshbach spectroscopy reveals an extraordinary rich

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