*Klaus Morawetz*

- Published in print:
- 2017
- Published Online:
- February 2018
- ISBN:
- 9780198797241
- eISBN:
- 9780191838743
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780198797241.003.0003
- Subject:
- Physics, Condensed Matter Physics / Materials

The classical non-ideal gas shows that the two original concepts of the pressure based of the motion and the forces have eventually developed into drift and dissipation contributions. Collisions of ...
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The classical non-ideal gas shows that the two original concepts of the pressure based of the motion and the forces have eventually developed into drift and dissipation contributions. Collisions of realistic particles are nonlocal and non-instant. A collision delay characterizes the effective duration of collisions, and three displacements, describe its effective non-locality. Consequently, the scattering integral of kinetic equation is nonlocal and non-instant. The non-instant and nonlocal corrections to the scattering integral directly result in the virial corrections to the equation of state. The interaction of particles via long-range potential tails is approximated by a mean field which acts as an external field. The effect of the mean field on free particles is covered by the momentum drift. The effect of the mean field on the colliding pairs causes the momentum and the energy gains which enter the scattering integral and lead to an internal mechanism of energy conversion. The entropy production is shown and the nonequilibrium hydrodynamic equations are derived. Two concepts of quasiparticle, the spectral and the variational one, are explored with the help of the virial of forces.Less

The classical non-ideal gas shows that the two original concepts of the pressure based of the motion and the forces have eventually developed into drift and dissipation contributions. Collisions of realistic particles are nonlocal and non-instant. A collision delay characterizes the effective duration of collisions, and three displacements, describe its effective non-locality. Consequently, the scattering integral of kinetic equation is nonlocal and non-instant. The non-instant and nonlocal corrections to the scattering integral directly result in the virial corrections to the equation of state. The interaction of particles via long-range potential tails is approximated by a mean field which acts as an external field. The effect of the mean field on free particles is covered by the momentum drift. The effect of the mean field on the colliding pairs causes the momentum and the energy gains which enter the scattering integral and lead to an internal mechanism of energy conversion. The entropy production is shown and the nonequilibrium hydrodynamic equations are derived. Two concepts of quasiparticle, the spectral and the variational one, are explored with the help of the virial of forces.

*K. Uchida, R. Ramos, and E. Saitoh*

- Published in print:
- 2017
- Published Online:
- December 2017
- ISBN:
- 9780198787075
- eISBN:
- 9780191829147
- Item type:
- chapter

- Publisher:
- Oxford University Press
- DOI:
- 10.1093/oso/9780198787075.003.0018
- Subject:
- Physics, Condensed Matter Physics / Materials

Chapter 18 This chapter discusses the spin Seebeck effect (SSE), which stands for the generation of a spin current, a flow of spinangular momentum, as a result of a temperature gradient in magnetic ...
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Chapter 18 This chapter discusses the spin Seebeck effect (SSE), which stands for the generation of a spin current, a flow of spinangular momentum, as a result of a temperature gradient in magnetic materials. In spintronics and spin caloritronics, the SSE is of crucial importance because it enables simple and versatile generation of a spin current from heat. Since the SSE is driven by thermally excited magnon dynaimcs, the thermal spin current can be generated not only from ferromagnetic conductors but also from insulators. Therefore, the SSE is applicable to “insulator-based thermoelectric conversion” which was impossible if only conventional thermoelectric technologies were used. In this chapter, after introducing basic characteristics and mechanisms of the SSE, important experimental progresses, such as the high-magnetic-field response of the SSE and the enhancement of the SSE in multilayer systems, are reviewed.Less

Chapter 18 This chapter discusses the spin Seebeck effect (SSE), which stands for the generation of a spin current, a flow of spinangular momentum, as a result of a temperature gradient in magnetic materials. In spintronics and spin caloritronics, the SSE is of crucial importance because it enables simple and versatile generation of a spin current from heat. Since the SSE is driven by thermally excited magnon dynaimcs, the thermal spin current can be generated not only from ferromagnetic conductors but also from insulators. Therefore, the SSE is applicable to “insulator-based thermoelectric conversion” which was impossible if only conventional thermoelectric technologies were used. In this chapter, after introducing basic characteristics and mechanisms of the SSE, important experimental progresses, such as the high-magnetic-field response of the SSE and the enhancement of the SSE in multilayer systems, are reviewed.