Journal club 22 06 08 superflow 4 He

Journal club 22. 06. 08

superflow 4 He Cuprates Ns – Ss Nc – PG – Sc Ns Ss Pressure (bar) Nc T (K) PG Sc Doping (h per Cu. O 2)

T (K) Cuprates (Bi 2 Sr 2 Ca. Cu 2 O 8) Nc – PG – Sc Y. Wang, L. Li and N. P. Ong Phys. Rev. B, 73, 024510 (2006) 0 T V PG (above Tc): No supercurrent Strong phase fluct’s B(T (K Nernst signal Strong pair amplitude Vortex liquid

Nc – PG – Sc T (K) Cuprates (Bi 2 Sr 2 Ca. Cu 2 O 8) Vortex liquid L. Li, Y. Wang, M. J. Naughton, S. Ono, Y. Ando and N. P. Ong, Europhys. Lett. , 72, 451 (2005) Nonlinear susceptibility B Incompressible Vortex liquid

T (K) 4 He Ns – Ss O. Penrose and L. Onsager, Phys. Rev. 104, 576 - 584 (1956): “…one would not expect B. E. condensation in a solid …” A. F. Andreev and I. M. Lifshitz Sov. Phys. JETP 29, 1107– 1113 (1969): “Quantum theory of defects in crystals” G. V. Chester, Phys. Rev. A 2, 256 - 258 (1970): “…interacting bosons … exhibit both crystalline order and B. E. condensation…” “…if there are vacancies…then a condensate exists…” A. J. Leggett, Phys. Rev. Lett. 25, 1543 - 1546 (1970): ”Nonclassical Rotational Inertia” A, w K

T (K) 4 He Ns – Ss E. Kim and M. H. W. Chan, Nature 427, 225 (2004) Nonlinear susceptibility A No direct observation of superflow A, w K

Cuprates Ns–”PG”–Ss Nc – PG – Sc T (K) Ns 4 He “PG” SS A Nonlinear cw No supercurrents found B Nonlinear c. B No supercurrents PG – Incompressible Vortex Liquid Strong pair amplitude + Strong phase fluctuations

4 He Cuprates Bosonic Neutral Fermionic Charged Bosonic PG = Vortex liquid Fermionic PG superflow The end