Historical research guide · 0080 · 2020
Quantum noise power devices
Garret Moddel · The Regents of the University of Colorado
In one minute
Garret Moddel filed this for the University of Colorado in 2020 and it was granted in 2022. His starting point is a familiar nuisance: every resistor makes electrical noise, and quantum theory says part of that noise never goes away, because it comes from the zero-point fluctuations of the vacuum rather than from heat. Ordinarily that noise is useless — it is the same everywhere, so nothing drives it anywhere. Moddel’s move is to break the symmetry with a Casimir cavity, two mirrors set so close together that some of the vacuum’s wavelengths will not fit between them. A resistor sitting against such a cavity is quieter than one in open space, and the patent pairs the two so the difference in noise power can be captured by a fast diode. He puts numbers on it — about 0.66 nanowatts from a single device up to a terahertz cut-off — and gives a fabrication recipe in micrometre-scale cells of chromium, silicon dioxide and aluminium, wired into series and parallel arrays.
Connection
Chapter 6 asks what a working vacuum-energy device actually looks like, and this is the patent behind one of the three programmes the site follows: it names the asymmetry, the materials, the cell size and the power per device, and Moddel’s own laboratory has already published a measured current from a metal-insulator-metal device with a submicron optical cavity on one side and no voltage applied.
From the source
A zero-point-energy-density-reducing structure — in the main example a Casimir cavity — placed against an electric device drives a flow of energy to or from that device, because the vacuum energy density inside the cavity is lower than outside it.Claim 1; Summary
The flow of energy occurs even in the absence of external sources of illumination, which is what separates these devices from solar cells and photodiodes: they are meant to produce power in the dark as well as in the light.Claim 4; Summary
The Johnson-Nyquist noise of a resistor carries an extra half-quantum term from zero-point energy, so that at low temperature or high frequency the voltage noise power spectrum tends to S(f) = 2R(f)hf and does not vanish.Detailed description, Equations 4 and 5
For a Casimir resistor connected through a high-frequency transmission line to a diode with a cut-off of one terahertz, the power available at a matched load is 0.66 nanowatts per device.Detailed description, Equation 7
The devices are fabricated at micrometre scale — a cell of about 2 by 3 micrometres, a 20-nanometre chromium layer serving as the resistor, and a cavity of 30 nanometres of silicon dioxide under 150 nanometres of aluminium acting as the mirror.Detailed description, Device fabrication
Individual cells are combined into series and parallel arrays — the worked example is 64 devices — so that the direct-current output voltage is the sum along a series path and the current the sum across parallel paths.Detailed description, FIG. 12
The way in
https://patents.google.com/patent/US11258379B2/enHow to cite it
Garret Moddel, The Regents of the University of Colorado (2020) Quantum noise power devices US11258379B2