Phys. Rev. Lett. 91, 250401 (2003) We have observed Bose-Einstein condensation of molecules. When a spin mixture
of fermionic Li-6 atoms was evaporatively cooled in an optical dipole trap near
a ...Feshbach resonance, the atomic gas was converted into Li_2 molecules. Below
600 nK, a Bose-Einstein condensate of up to 900,000 molecules was identified by
the sudden onset of a bimodal density distribution. This condensate realizes
the limit of tightly bound fermion pairs in the crossover between BCS
superfluidity and Bose-Einstein condensation.
Schunck Peter. Problèmes de la traduction en allemand de la littérature francophone africaine. In: Équivalences, 14e année-n°2-3, 1983. La traduction et l'interprétation : réalités et perspectives. ...pp. 29-40.
Aspects of chalone action Lehmann, W; Graetz, H; Schunck, H ...
Acta histochemica. Supplementband,
1983, Letnik:
27
Journal Article
Recenzirano
The following aspects of action of a chalone-like factor for the Ehrlich ascites mammary carcinoma and of the granulocytic chalone are discussed: 1) Dependence on the state of proliferation. Rapidly ...growing cells respond poorly or not at all. 2) Antagonism with growth factors. The factor for the Ehrlich ascites mammary carcinoma is antagonized by physiological concentrations of insulin or by proinsulin. The granulocytic chalone is antagonized by colony stimulating factor. 3) Influence on cell cycle progression. Attempts and problems to analyse this influence for the factor for the Ehrlich ascites mammary carcinoma by flow cytometry are described.
We have observed phase separation between the superfluid and the normal component in a strongly interacting Fermi gas with imbalanced spin populations. The in situ distribution of the density ...difference between two trapped spin components is obtained using phase-contrast imaging and 3D image reconstruction. A shell structure is clearly identified where the superfluid region of equal densities is surrounded by a normal gas of unequal densities. The phase transition induces a dramatic change in the density profiles as excess fermions are expelled from the superfluid.
More than half a century after the fundamental, spherical shell structure in nuclei has been established, theoretical predictions indicate that the shell-gaps comparable or even stronger than those ...at spherical shapes may exist. Group-theoretical analysis supported by realistic mean-field calculations indicate that the corresponding nuclei are characterized by the \(T_d^D\) ('double-tetrahedral') group of symmetry, exact or approximate. The corresponding strong shell-gap structure is markedly enhanced by the existence of the 4-dimensional irreducible representations of the group in question and consequently it can be seen as a geometrical effect that does not depend on a particular realization of the mean-field. Possibilities of discovering the corresponding symmetry in experiment are discussed.
ActaPhys.Polon.B38:1437-1446,2007 Exotic-deformation effects in 46Ti nucleus were investigated by analysing the
high-energy gamma-ray and the alpha-particle energy spectra. One of the
experiments was ...performed using the charged-particle multi-detector array ICARE
together with a large volume (4"x4") BGO detector. The study focused on
simultaneous measurement of light charged particles and gamma-rays in
coincidence with the evaporation residues. The experimental data show a
signature of very large deformations of the compound nucleus in the Jacobi
transition region at the highest spins. These results are compared to data from
previous experiments performed with the HECTOR array coupled to the EUROBALL
array, where it was found that the GDR strength function is highly fragmented,
strongly indicating a presence of nuclei with very large deformation.
Phys.Rev.A71:045601,2005 Feshbach resonances in lithium-6 were experimentally studied and
theoretically analyzed. In addition to two previously known s-wave resonances,
we found three p-wave ...resonances. Four of these resonances are narrow and yield
a precise value of the singlet scattering length, but do not allow us to
accurately predict the location of the broad resonance near 83 mT. Its position
was previously measured in a molecule-dissociation experiment for which we,
here, discuss systematic shifts.
Phys. Rev. Lett. 91, 160401 (2003) We have produced a quantum degenerate Li-6 Fermi gas with up to 7 x 10^7
atoms, an improvement by a factor of fifty over all previous experiments with
degenerate ...Fermi gases. This was achieved by sympathetic cooling with bosonic
Na-23 in the F=2, upper hyperfine ground state. We have also achieved
Bose-Einstein condensation of F=2 sodium atoms by direct evaporation.
The formation time of a condensate of fermionic atom pairs close to a Feshbach resonance was studied. This was done using a phase-shift method in which the delayed response of the many-body system to ...a modulation of the interaction strength was recorded. The observable was the fraction of condensed molecules in the cloud after a rapid magnetic field ramp across the Feshbach resonance. The measured response time was slow compared to the rapid ramp, which provides final proof that the molecular condensates reflect the presence of fermion pair condensates before the ramp.
Quantum-degenerate Fermi gases provide a remarkable opportunity to study strongly interacting fermions. In contrast to other Fermi systems, such as superconductors, neutron stars or the quark-gluon ...plasma, these gases have low densities and their interactions can be precisely controlled over an enormous range. Here we report observations of vortices in such a gas that provide definitive evidence for superfluidity. By varying the pairing strength between two fermions near a Feshbach resonance, one can explore the crossover from a Bose-Einstein condensate (BEC) of molecules to a Bardeen-Cooper-Schrieffer (BCS) superfluid of loosely bound pairs whose size is comparable to, or even larger than, the interparticle spacing. The crossover realizes a novel form of high-T_C superfluidity and it may provide new insight for high-T_C superconductors. Previous experiments with Fermi gases have revealed condensation of fermion pairs. While these and other studies were consistent with predictions assuming superfluidity, the smoking gun for superfluid behavior has been elusive. Our observation of vortex lattices directly displays superfluid flow in a strongly interacting, rotating Fermi gas.
