Crossover from phonon-limited to pair-breaking limited critical velocity
D. E. Miller, J. K. Chin and C. A. Stan, Y. Liu, W. Setiawan, C. Sanner and W. Ketterle:
Critical velocity for superfluid flow across the BEC-BCS crossover.
Phys. Rev. Lett. 99 , 070402 (2007).
Link

Excitations during quantum reflection
T. A. Pasquini, M. Saba, G. Jo, Y. Shin, W. Ketterle, D. E. Pritchard, T. A. Savas, N. Mulders:
Low velocity quantum reflection of Bose-Einstein condensates.
Phys. Rev. Lett. 97 , 260402 (2006).
Link

Amplification of phonon excitations:
Instability of a BEC with negative scattering length
J.K. Chin, J.M. Vogels, and W. Ketterle:
Amplification of Local Instabilities in a Bose-Einstein Condensate with Attractive Interactions.
Phys. Rev. Lett. 90, 160405 (2003).
Link

Analysis of the phonon wavefunction
J.M. Vogels, K. Xu, C. Raman, J.R. Abo-Shaeer, and W. Ketterle:
Experimental observation of the Bogoliubov transformation for a Bose-Einstein condensed gas.
Phys. Rev. Lett. 88, 060402 (2002).
Link

Surface excitations in a BEC
R. Onofrio, D.S. Durfee, C. Raman, M. Köhl, C.E. Kuklewicz, and W. Ketterle:
Surface excitations of a Bose-Einstein condensate.
Phys. Rev. Lett. 84, 810-813 (2000).
Link

Phonon excitation
.D.M. Stamper-Kurn, A.P. Chikkatur, A. Görlitz, S. Inouye, S. Gupta, D.E. Pritchard, and W. Ketterle:
Excitation of phonons in a Bose-Einstein condensate by light scattering.
Phys. Rev. Lett. 83, 2876-2879 (1999).
Link

Finite temperature collective excitations
D.M. Stamper-Kurn, H.-J. Miesner, S. Inouye, M.R. Andrews, and W. Ketterle:
Collisionless and hydrodynamic excitations of a Bose-Einstein condensate.
Phys. Rev. Lett. 81, 500-503 (1998).
Link

Sound propagation
M.R. Andrews, D.M. Kurn, H.-J. Miesner, D.S. Durfee, C.G. Townsend, S. Inouye,
and W. Ketterle:
Propagation of sound in a Bose-Einstein condensate.
Phys. Rev. Lett. 79, 549-552 (1997);  Erratum: Phys. Rev. Lett. 80, 2967 (1998).
Link

Collective excitations
M.-O. Mewes, M.R. Andrews, N.J. van Druten, D.M. Kurn, D.S. Durfee, C.G. Townsend, and W. Ketterle:
Collective excitations of a Bose-Einstein condensate in a magnetic trap.
Phys. Rev. Lett. 77, 988-991 (1996).
Link