Surface-induced order parameter distortion in superfluid ³He-B measured by nonlinear NMR.
The B phase of superfluid 3He is a three-dimensional time-reversal invariant topological superfluid, predicted to support gapless Majorana surface states. We confine superfluid 3He into a thin nanofluidic slab geometry. In the presence of a weak symmetry-breaking magnetic field, we have observed two possible states of the confined 3He-B phase manifold, through the small tipping angle NMR response. Large tipping angle nonlinear NMR has allowed the identification of the order parameter of these states and enabled a measurement of the surface-induced gap distortion. The results for two different quasiparticle surface scattering boundary conditions are compared with the predictions of weak-coupling quasiclassical theory. We identify a textural domain wall between the two B phase states, the edge of which at the cavity surface is predicted to host gapless states, protected in the magnetic field.
Department of Physics, Royal Holloway University of London, Egham, TW20 0EX Surrey, United Kingdom.
Lev V
LV
Levitin
Department of Physics, Royal Holloway University of London, Egham, TW20 0EX Surrey, United Kingdom and Department of Physics, Cornell University, Ithaca, New York 14853, USA.
Robert G
RG
Bennett
Kapitza Institute for Physical Problems, ul. Kosygina 2, Moscow 119334, Russia.
Evgeny V
EV
Surovtsev
Department of Physics, Cornell University, Ithaca, New York 14853, USA.
Jeevak M
JM
Parpia
Department of Physics, Royal Holloway University of London, Egham, TW20 0EX Surrey, United Kingdom.
Brian
B
Cowan
Department of Physics, Royal Holloway University of London, Egham, TW20 0EX Surrey, United Kingdom.
Andrew J
AJ
Casey
Department of Physics, Royal Holloway University of London, Egham, TW20 0EX Surrey, United Kingdom.
John
J
Saunders