TY - JOUR

T1 - A levitated droplet of superfluid He-3-B entirely surrounded by He-3-A.

AU - Bradley, D. Ian

AU - Fisher, Shaun N.

AU - Guénault, A.M.

AU - Haley, Richard P.

AU - Martin, H.

AU - Pickett, George R.

AU - Roberts, John E.

AU - Tsepelin, Viktor

PY - 2006

Y1 - 2006

N2 - From our long experience of using profiled magnetic fields to stabilize and manipulate the A-B phase boundary in superfluid He-3, we have constructed a cell in which we can create and move a droplet of B phase, levitated within A phase away from any walls at T similar to 0.15 T-c. Uniquely, the A and B condensates are coherent across the A-B interface and at such low temperatures the superfluid is essentially pure, providing the most ordered phase boundary to which we have laboratory access. We configure the field so that within a bulk volume of superfluid, a region of high field (stabilizing the A phase) completely surrounds a region of lower field (stabilizing the B phase). Our preliminary measurements are at zero pressure and temperatures below 0.3T(c) where the first-order transition from B to A phase is at 340 mT. We observe the formation of the droplet as we ramp the field, and we also study the transport of thermal excitations out of the droplet. Future plans include measurements at higher pressures where the A phase can be stabilized in low magnetic field at temperatures close to T-c. Upon cooling into the B phase we should then be able to make the first studies of nucleation uninfluenced by the presence of container walls.

AB - From our long experience of using profiled magnetic fields to stabilize and manipulate the A-B phase boundary in superfluid He-3, we have constructed a cell in which we can create and move a droplet of B phase, levitated within A phase away from any walls at T similar to 0.15 T-c. Uniquely, the A and B condensates are coherent across the A-B interface and at such low temperatures the superfluid is essentially pure, providing the most ordered phase boundary to which we have laboratory access. We configure the field so that within a bulk volume of superfluid, a region of high field (stabilizing the A phase) completely surrounds a region of lower field (stabilizing the B phase). Our preliminary measurements are at zero pressure and temperatures below 0.3T(c) where the first-order transition from B to A phase is at 340 mT. We observe the formation of the droplet as we ramp the field, and we also study the transport of thermal excitations out of the droplet. Future plans include measurements at higher pressures where the A phase can be stabilized in low magnetic field at temperatures close to T-c. Upon cooling into the B phase we should then be able to make the first studies of nucleation uninfluenced by the presence of container walls.

KW - superfluid

KW - helium-3

KW - interface

KW - droplet

U2 - 10.1063/1.2354621

DO - 10.1063/1.2354621

M3 - Journal article

VL - 850

SP - 95

EP - 96

JO - AIP Conference Proceedings

JF - AIP Conference Proceedings

SN - 0094-243X

ER -