TY - JOUR

T1 - Mesoscopic behaviour of the neutral Fermi gas He-3 confined in quantum wires

AU - Phillipson, SL

AU - Guénault, A.M.

AU - Fisher, SN

AU - Pickett, GR

AU - Thibault, PJY

PY - 1998/10/8

Y1 - 1998/10/8

N2 - The behaviour of electron gases in restricted geometries provides a means to explore the fundamental quantum-mechanical properties of fermion gases at mesoscopic length scales(1). But the existence of Coulomb repulsion between electrons unavoidably complicates the physics. Quantum gases of neutral fermions-such as He-3 quasiparticles in a dilute solution of He-3 in He-4, cooled to millikelvin temperatures(2)-therefore offer a means of probing regimes completely inaccessible to electronic systems. Here we demonstrate the quantum exclusion of a He-3 fermion gas from a network of narrow channels, connected to a reservoir of He-3/He-4 solution. The effect is expected from simple quantum-mechanical arguments, which predict that the He-3 atoms cannot enter the channels when their wavelength exceeds root 2 times the channel width. By adjusting the temperature of the solution, the energy of the particles and hence their average wavelength can be controlled. In this way, we observe temperature-dependent changes in the penetration of the 3He quasiparticles into the channels. Our results demonstrate the macroscopic response of an atomic gas to basic quantum-mechanical restrictions at the mesoscopic level.

AB - The behaviour of electron gases in restricted geometries provides a means to explore the fundamental quantum-mechanical properties of fermion gases at mesoscopic length scales(1). But the existence of Coulomb repulsion between electrons unavoidably complicates the physics. Quantum gases of neutral fermions-such as He-3 quasiparticles in a dilute solution of He-3 in He-4, cooled to millikelvin temperatures(2)-therefore offer a means of probing regimes completely inaccessible to electronic systems. Here we demonstrate the quantum exclusion of a He-3 fermion gas from a network of narrow channels, connected to a reservoir of He-3/He-4 solution. The effect is expected from simple quantum-mechanical arguments, which predict that the He-3 atoms cannot enter the channels when their wavelength exceeds root 2 times the channel width. By adjusting the temperature of the solution, the energy of the particles and hence their average wavelength can be controlled. In this way, we observe temperature-dependent changes in the penetration of the 3He quasiparticles into the channels. Our results demonstrate the macroscopic response of an atomic gas to basic quantum-mechanical restrictions at the mesoscopic level.

U2 - 10.1038/26927

DO - 10.1038/26927

M3 - Journal article

VL - 395

SP - 578

EP - 580

JO - Nature

JF - Nature

SN - 0028-0836

IS - 6702

ER -