Superfluid density from heat-pulse propagation near the lambda line in 4He-aerogel systems.
Superfluid density from heat-pulse propagation near the lambda line in 4He-aerogel systems.
复制标题
4He-气凝胶系统中 lambda 线附近热脉冲传播产生的超流体密度。
DOI：
10.1103/physrevlett.67.695
复制
发表时间：
1991
影响因子：
8.6
通讯作者：
G. Ahlers
中科院分区：
文献类型：
--
作者：
Norbert Mulders;Ravi Mehrotra;Lori S. Goldner;G. Ahlers
We determined the superfluid density {rho}{sub {ital s}} from the speed of heat pulses, using a hydrodynamic model that contains coupling between the aerogel and the helium. To investigate the universality of the exponent of {rho}{sub {ital s}}, measurements of {rho}{sub {ital s}} were taken from saturated vapor pressure to 29 bars. Fitting {rho}{sub {ital s}} with a pure power law in reduced temperature leads to a pressure-dependent exponent. Inclusion of a confluent singular term in the fits reveals a pressure-independent exponent {zeta}=0.755{plus minus}0.003 which differs from {zeta}=0.672 for bulk helium.
We determined the superfluid density {rho}{sub {ital s}} from the speed of heat pulses, using a hydrodynamic model that contains coupling between the aerogel and the helium. To investigate the universality of the exponent of {rho}{sub {ital s}}, measurements of {rho}{sub {ital s}} were taken from saturated vapor pressure to 29 bars. Fitting {rho}{sub {ital s}} with a pure power law in reduced temperature leads to a pressure-dependent exponent. Inclusion of a confluent singular term in the fits reveals a pressure-independent exponent {zeta}=0.755{plus minus}0.003 which differs from {zeta}=0.672 for bulk helium.