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Research output: Contribution to Journal/Magazine › Letter › peer-review
Research output: Contribution to Journal/Magazine › Letter › peer-review
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TY - JOUR
T1 - Multimode probing of superfluid 4He by tuning forks
AU - Guthrie, Andrew
AU - Haley, Richard
AU - Jennings, Ash
AU - Kafanov, Sergey
AU - Kolosov, Oleg
AU - Mucientes, Marta
AU - Noble, Theo
AU - Pashkin, Yuri
AU - Pickett, George
AU - Tsepelin, Viktor
AU - Zmeev, Dmitry
AU - Efimov, Viktor
PY - 2019/9/13
Y1 - 2019/9/13
N2 - Flexural mode vibrations of miniature piezoelectric tuning forks (TF) are known to be highly sensitive to superfluid excitations and quantum turbulence in 3He and 4He quantum fluids, as well as to the elastic properties of solid 4He, complementing studies by large scale torsional resonators. Here we explore the sensitivity of a TF, capable of simultaneously operating in both the flexural and torsional modes, to excitations in the normal and superfluid 4He. Thetorsional mode is predominantly sensitive to shear forces at the sensor - fluid interface and much less sensitive to changes in the density of the surrounding fluid when compared to the flexural mode. Although we did not reach thecritical velocity for quantum turbulence onset in the torsional mode, due to its order of magnitude higher frequency and increased acoustic damping, the torsional mode was directly sensitive to fluid excitations, linked to quantum turbulence created by the flexural mode. The combination of two dissimilar modes in a single TF sensor can provide a means to study the details of elementary excitations in quantum liquids, and at interfaces between solids and quantum fluid.
AB - Flexural mode vibrations of miniature piezoelectric tuning forks (TF) are known to be highly sensitive to superfluid excitations and quantum turbulence in 3He and 4He quantum fluids, as well as to the elastic properties of solid 4He, complementing studies by large scale torsional resonators. Here we explore the sensitivity of a TF, capable of simultaneously operating in both the flexural and torsional modes, to excitations in the normal and superfluid 4He. Thetorsional mode is predominantly sensitive to shear forces at the sensor - fluid interface and much less sensitive to changes in the density of the surrounding fluid when compared to the flexural mode. Although we did not reach thecritical velocity for quantum turbulence onset in the torsional mode, due to its order of magnitude higher frequency and increased acoustic damping, the torsional mode was directly sensitive to fluid excitations, linked to quantum turbulence created by the flexural mode. The combination of two dissimilar modes in a single TF sensor can provide a means to study the details of elementary excitations in quantum liquids, and at interfaces between solids and quantum fluid.
U2 - 10.1063/1.5121023
DO - 10.1063/1.5121023
M3 - Letter
VL - 115
JO - Applied Physics Letters
JF - Applied Physics Letters
SN - 0003-6951
IS - 11
M1 - 113103
ER -