Details

Autor(en) / Beteiligte

• Cladé, P
• Ryu, C
• Ramanathan, A
• Helmerson, K
• Phillips, W D

Titel

Observation of a 2D Bose gas: from thermal to quasicondensate to superfluid

Ist Teil von

• Physical review letters, 2009-05, Vol.102 (17), p.170401-170401, Article 170401

Ort / Verlag

United States

Erscheinungsjahr

2009

Quelle

APS_美国物理学会过刊

Beschreibungen/Notizen

• We present experimental results on a Bose gas in a quasi-2D geometry near the Berezinskii, Kosterlitz, and Thouless (BKT) transition temperature. By measuring the density profile after time of flight and the coherence length, we identify different states of the gas. We observe that the gas develops a bimodal distribution without long range order. In this regime, the gas presents a longer coherence length than the thermal cloud; it is quasicondensed but is not superfluid. Experimental evidence indicates that we also observe the superfluid transition (BKT transition). For a sufficiently long time of flight, we observe a trimodal distribution when the gas has developed a superfluid component.