Excitations in Two-Dimensional and Three-Dimensional Quantum Fluids

✍ Scribed by Henry R. Clyde (auth.), A. F. G. Wyatt, H. J. Lauter (eds.)

• Publisher: Springer US
• Year: 1991
• Tongue: English
• Leaves: 582
• Series: NATO ASI Series 257
• Edition: 1
• Category: Library

✦ Synopsis

The study of quantum fluids in three dimensions has been an important area for many years as it embraces Bose-Einstein condensation, superfluidity and macroscopic quantisation. These are fundamental aspects of physics which can be studied in liquid 4He. In contrast, quantum fluids in two dimension is more recent and less developed. Nevertheless it has shown many interesting phenomena including a rich variety of phases and the Kosterlitz-Thouless transition. Intermediate between these dimensions are the restricted geometries of micro porous materials into which He may be introduced. The main quantum materials considered are 4He, 3He, D2, H2, H and electrons on the surface of 4He. The superfluid phases of 3He were excluded, e~cept for superfluid film flow, as 3He involves a separate set of problems. These proceedings arise from a lively Advanced Research Workshop on Excitations in Two-Dimensional and Three-Dimensional Quantum Fluids held in Exeter 10-15 August 1990. Fifty scientists took part and each provided a written contribution. Perhaps it is a testimony to the discussions that several papers were revised by the authors after the meeting. The order of the chapters is the same as the presentations at the workshop. This arrangement starts with 4He in three dimensions which establishes a base from which the two dimensional properties can be viewed. At the end of each section there is a report on the discussion session. These are interesting and useful chapters as they clarify points made in the papers and define the boundary of current understanding.

✦ Table of Contents

Front Matter....Pages i-x
Excitations in Liquid 4 He....Pages 1-13
Excitations in Superfluid 4 He and the Dielectric Formalism....Pages 15-23
Recent High-Resolution Neutron Scattering Studies of Liquid 4 He....Pages 25-46
Momentum Distributions in Liquid Helium....Pages 47-58
S(Q, ω ) for Liquid 4 He: What More do We Need to Know?....Pages 59-76
Raman Scattering from Superfluid Helium....Pages 77-89
Interpretation of Inelastic Light Scattering Measurements in 4 He....Pages 91-102
Discussion on Excitations in Bulk 4 He....Pages 103-106
Excitations in Liquid Helium at Negative Pressures....Pages 107-117
Neutron Spin Echo Observation of Spontaneous Phonon Decay in Superfluid 4 He....Pages 119-120
Dynamics of Rotons....Pages 121-130
Spectroscopic Study of Scattering of UCN by Liquid He 4 ....Pages 131-135
Roton-Roton Scattering....Pages 137-147
Theory of Roton-Roton Scattering....Pages 149-157
Theory of the Phonon-Roton Spectrum of Liquid 4 He....Pages 159-171
Towards a Unified Description of Bulk Excitations and the Two Fluid Theory of Superfluids in Terms of a Single Classical Equation of Motion....Pages 173-177
Disscussion on Bulk 4 He Dynamics....Pages 179-181
Bulk Properties of 3 He- 4 He Mixtures....Pages 183-194
Transport Properties of Very Dilute Superfluid Mixtures of 3 He in 4 He....Pages 195-203
Anomalous Thermal Conductivity in Very Dilute 3 He- 4 He Solutions....Pages 205-220
Thermal Counterflow in Superfluid 3 He- 4 He Mixtures....Pages 221-229
Elementary Excitations in Fermi Liquids: Neutron Scattering by 3 He and 3 He- 4 He Mixtures....Pages 231-238
The Effect of Film Thickness and the Substrate on Superfluid 3 He Film Flow....Pages 239-250
Discussion on Bulk 3 He and 3 He/ 4 He Mixtures....Pages 251-255
Collective Excitations and Fermi-Liquid Effects in 4 HE and 3 He- 4 He Films....Pages 257-268
NMR Measurements of 3 He in 3 He- 4 He Mixture Films....Pages 269-279
Fermion Oceans....Pages 281-290
Studies of Dissipative Superflow through Porous Vycor Glass....Pages 291-300
Low Temperature Heat Capacity of 4 He Films in Vycor....Pages 301-309
Vortices and the Superfluid 4 He Phase Transition in Two and Three Dimensions....Pages 311-322
Scaling of Confined 4 He at the Superfluid Transition....Pages 323-333
Dynamics of Helium Clusters....Pages 335-342
Phase-Slippage Studies of the Critical Velocity in Helium-4....Pages 343-356
Discussion on Restricted Geometry....Pages 357-359
The Inertia of the 4 He Crystal Surface and the Calculation of the Phonon Transmission....Pages 361-374
Thermal Excitations and Helium 3 Crystallization....Pages 375-386
Anisotropy of Surface Stiffness, Growth Kinetics and Roughening Transition in 4 He....Pages 387-395
Liquid-Solid 4 He Interface: Equilibrium Shape and Exitations....Pages 397-406
Charge Motion in Solid Helium....Pages 407-417
4 He Films on Graphite Studied by Neutron Scattering....Pages 419-427
Interface between Two Thin 3 He- 4 He Liquid Mixtures Films....Pages 429-437
Discussion on Interfaces....Pages 439-443
Adsorbed Quantum Gases....Pages 445-451
Nuclear Magnetism of 3 He Films Adsorbed on the Surface of Graphite....Pages 453-466
Low-Field NMR Studies of the Boundary Layers of 3 He on Grafoil....Pages 467-476
Search for a Fluid Phase in Films of Molecular Hydrogen Isotopes Adsorbed on MgO....Pages 477-488
Lattice Dynamics of Quantum Gases Adsorbed on Graphite Investigated by Inelastic Neutron Scattering....Pages 489-498
Thermodynamic and Neutron-Diffraction Studies of H 2 and D 2 Multilayers Physisorbed on Graphite....Pages 499-510
Scattering of Atomic Hydrogen from the Surface of Liquid Helium Films....Pages 511-519
Discussion on Adsorbates....Pages 521-526
Electrons at the Surface of Quantum Systems....Pages 527-537
Electrons on Helium Films....Pages 539-548
Tunneling and Evaporation from the Electron Liquid Trapped at a Helium Surface....Pages 549-555
Electrons on Helium in a Quantizing Magnetic Field....Pages 557-566
Vortex Creation in Superfluid Helium-4....Pages 567-578
Ions Trapped below the Surface of Superfluid Helium....Pages 579-584
Discussion on Ions/Electrons....Pages 585-588
Final Discussion Session....Pages 589-593
Back Matter....Pages 595-598

✦ Subjects

Atomic, Molecular, Optical and Plasma Physics;Electrical Engineering;Theoretical, Mathematical and Computational Physics