Abstract
We have made heat capacity measurements of superfluid 4He at temperatures very close to the lambda point, T λ, in a constant heat flux, Q, when the helium sample is heated from above. In this configuration the helium enters a self-organized (SOC) heat transport state at a temperature T soc(Q), which for Q≥100 nW/cm2 lies below T λ. At low Q we observe little or no deviation from the Q=0 heat capacity up to T SOC(Q); beyond this temperature the heat capacity appears to be sharply depressed, deviating dramatically from its bulk behaviour. This marks the formation and propagation of a SOC/superfluid two phase state, which we confirm with a simple model. The excellent agreement between data and model serves as an independent confirmation, of the existence of the SOC state. As Q is increased (up to 6 µW/cm2) we observe a Q dependent depression in the heat capacity that occurs just below T SOC(Q), when the entire sample is still superfluid, This is due to the emergence of a large thermal resistance in the sample, which we have measured and used to model the observed heat capacity depression. Our measurements of the superfluid thermal resistivity are a factor of ten larger than previous measurements by Baddar et al.
Similar content being viewed by others
REFERENCES
R. Haussmann, V. Dohro, Phys. Rev. B 46, 6361 (1992)
R. Haussmann, Phys. Rev. B 60, 12349 (1999)
T. C. P. Chuff, D. L. Goodstein, A. W. Harter, R. Mukhopadhyay, Phys. Rev. Lett. 77, 1793 (1996)
R. Haussman, V. Dohro, Czech. J. Phys. 46-51, 171 (1996)
R. V. Duncan, G. Ahlers, V. Steinberg, Phys. Rev. Lett. 60, 1522 (1988)
A. W. Harter, R. A. M. Lee, A. Chatto, X. Wu, T. C. P. Chuff, D. L. Goodstein, Phys. Rev. Lett. 84, 2195 (2000)
G. Ahlers, F. C. Liu, J. Low Temp. Phys. 105, 225 (1996)
W. A. Moeur, P. K. Day, F.-C. Liu, S. T. P. Boyd, M. J. Adriaans, R. V. Duncan, Phys. Rev. Lett. 78, 2421 (1997)
P. B. Weichman, J. Miller, J. Low Temp. Phys. 119, 155 (2000)
B. J. Klemme, M. J. Adriaans, P. K. Day, D. A. Sergatskov, T. L. Aselage, R. V. Duncan, J. Low Temp. Phys. 116, 133 (1999)
Note, the cell had a vapour bubble that was larger than this dead volume,rendering the sample space 88 to 98% full depending on the particular run.
J. A. Lipa, D. R. Swanson, J. A. Nissen, T. C. P. Chuff, U. E. Israelsson, Phys. Rev. Lett. 76, 944 (1996)
W. T. Tam, G. Ahlers, Phys. Rev. B 33, 183 (1986)
M. Dingus, F. Zhong, H. Meyer, J. Low Temp. Phys. 65, 1522 (1988)
S. T. P. Boyd, R. A. M. Lee, R. V. Duncan, D. L. Goodstein, to be published, J. Low Temp. Phys.
H. Baddar, G. Ahlers, K. Kuehn, H. Fu, J. Low Temp. Phys. 119, 1 (2000)
A. P. Firme, T. Araki, R. Blaauwgeers, V. B. Egtsov, N. B. Kopnin, M. Krusius, L. Skrbek, M. Tsubota, G. E. Volovik, to be published Nature (2003)
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Lee, R.A.M., Chatto, A.R., Sergatskov, D.A. et al. ‘Heat from Above’ Heat Capacity Measurements in Liquid 4He. Journal of Low Temperature Physics 134, 495–505 (2004). https://doi.org/10.1023/B:JOLT.0000012601.63124.60
Issue Date:
DOI: https://doi.org/10.1023/B:JOLT.0000012601.63124.60