Noise in physical systems

 

Transport properties are naturally fluctuating and thus involve noise. This topic is well known in electronics, as the Johnson or Nyquist noise of a resistor in thermal equilibrium.
The most ubiquitous noise is so-called flicker noise or 1/f-noise, that appears at many places in nature, including the yearly levels of the river Nile (before the Assuan Dam), and all kinds of classical and popular music, except jazz: "good" music has a 1/f-spectrum, expressing a harmony in short versus long tones and pauses.
- Several investigations were made, [P9], [P11], [P15],[L4]. A nice small work did not get further than a conference proceedings, [C4]; someday it will be put on cond-mat.
- A dramatically wrong "quantum theory of 1/f-noise" (the worst part of physics I ever saw) was presented with much verbal power in a series of conferences on Noise in Physical Systems by a certain mr. Handel. Experimentalists who felt that this theory was of no value were lacking scientific arguments against his ongoing questions why their data were not interpreted within this theory. For years they begged theorist to look into this matter. I took up the challenge, starting with selecting and convincing two co-authors. A long series of objections against this theory was written down in [P13], and it served its purpose. The real task was actually to dig out all possible small papers Handel wrote in this field and comment on them, because else he would claim that just there was the proper derivation - whatever they were actually about.

 

[C4] Th.M. N. and M.H. Ernst, Properties of 1/f-noise in hopping models, in ``Noise in Physical systems and 1/f-noise'', A.D.A Amico and P. Mazetti, eds. (North Holland, Amsterdam, 1986) 365-368

[L4] Th.M. N. and M.H. Ernst 1/f-noise in a d-dimensional hopping model with static disorder, Phys. Rev. B 33 (1986) 2824-2827

[P11] Th.M. N. and M.H. Ernst, Excess noise in a hopping model for a resistor with quenched disorder, J. Stat. Phys. 41 (1985) 773-801

[P9] J. Machta, M. Nelkin, Th.M. N. and M.H. Ernst, 1/f-noise in a hopping model with trapping, Phys. Rev. B 31 (1985) 7636-7642

[P13] Th.M. N., D. Frenkel, and N.G. van Kampen, Objections to Handel's quantum theory of 1/f-noise, Phys. Rev. A 35 (1987) 2750-2753