Piezoelectricity-induced Room Temperature Superconductor

Salvatore Cezar Pais, Piezoelectricity-induced Room Temperature Superconductor, United States patent application US20190058105A1, application 15/678,672, filed 16 August 2017, published 21 February 2019, assigned to the Department of the Navy. Abandoned. Record at patents.google.com/patent/US20190058105A1/en.

Abstract

The present invention is a room temperature superconductor comprising of a wire, which comprises of an insulator core and a metal coating. The metal coating is disposed around the insulator core, and the metal is coating deposited on the core. When a pulsed current is passed through the wire, while the wire is vibrated, room temperature superconductivity is induced.

Statement of government interest

The invention described herein may be manufactured and used by or for the Government of the United States of America for governmental purposes without payment of any royalties thereon or therefor.

Background

A room-temperature superconductor is a material that is capable of exhibiting superconductivity at operating temperatures of or above 25 degrees Celsius (approx. 300 degrees Kelvin). Several materials have been reported to be room-temperature superconductors, although none of these reports has been confirmed. However, instead of concentrating on the chemical structure of such materials which do not utilize any electrical or mechanical manipulation, room temperature superconductivity (RTSC) in a manipulated current-carrying special composite metal wire may be achieved. The current must be pulsed for maximum effect. This concept enables the transmission of electrical power without any losses and exhibits optimal thermal management (no heat dissipation), which leads to the design and development of novel energy generation and harvesting devices with enormous benefits to civilization.

Simply put, RTSC can be enabled in a current carrying special composite metal wire which is abruptly vibrated by mechanical, magnetic, electrical, and/or electromagnetic means. The wire is a bulk (core) insulator with a 'thin' coating of a normal metal (such as Aluminum) or other practicable coating. The coating has a thickness on the order of the London penetration depth (but possibly much thicker), and an externally applied magnetic field is applied to the metal. For the electrically-driven vibration, the wire is coated with lead zirconate titanate (PZT ceramic/poor metal), or any other material in which the piezoelectric effect can be induced. Since the RTSC supercurrent may be generated along the metal/insulator interface (boundary), this wire configuration can be termed an unconventional superconductor.

Summary

The present invention is directed to a piezoelectricity-induced room temperature superconductor that includes a wire comprising an insulator core and a coating, the coating disposed around the insulator core, the coating deposited on the core, the coating undergoes polarizing treatment after the deposition, and, when a pulsed current is passed through the wire, room temperature superconductivity is induced.

It is a feature of the present invention to provide a piezoelectricity-induced room temperature superconductor that enables the transmission of electrical power with no losses.

It is a feature of the present invention to provide a piezoelectricity-induced room temperature superconductor that superconductivity is achieved from abrupt/accelerated vibration of a wire through use of a pulsed current through the wire.

Description

The enablement of RTSC relates to the superconducting (SC) material chemical structure, but a great deal more to do with what is 'done' to the material to make it SC, from a far-from-equilibrium perspective (non-equilibrium thermodynamics). It is important to realize that internal heating within any system enclosure can be greatly reduced by room temperature (300 deg. Kelvin and higher) superconducting wiring, which would allow for lossless transmission of electrical power to its subsystems.

There are three parameters which affect superconductivity. The parameters include temperature, current density, and externally applied magnetic field strength. Physically, these parameters have in common one thing, that is, the interactive motion of electric charges, namely electrons. Control of this motion via vibration and/or spin of charged matter subjected to rapid acceleration transients (highly non-linear in nature) may lead to the achievement of room temperature superconductivity, especially if the charged matter is inhomogeneous.

At the present time, it is believed that the mechanism of superconductivity can be induced either by bipolarons or Cooper pairing. The important realization is that independent of physical mechanism, the key to observed superconductivity is the strong electron-lattice (phonon) coupling. Strong electron-lattice interactions can be obtained from abrupt/accelerated vibration of a wire; thereby, providing justification for RTSC enablement. As a result, a special composite metallic wire can become superconductive (SC) at room temperature, if you make it abruptly vibrate, while running a pulsed current through it, just like 'plucking' a guitar string intermittently. The current must be pulsed for maximum effect.

In one of the embodiments of the invention, the wire is a special composite metal wire that may be comprised of a bulk (core) insulator (such as Teflon, or any other non-conductive polymer) with a 'thin' coating of a normal metal (aluminum) or poor metal (PZT ceramic). The coating has a thickness on the order of the below described London penetration depth (but possibly much thicker), and the wire is given an externally applied magnetic field. Arguably, this wire configuration may be termed an unconventional superconductor, since the RTSC supercurrent may be generated along the interface (boundary) between the coating and the core insulator of the wire. This is due to the abrupt change in state between the coating and the insulator core, analogous to an abrupt phase transition occurring along the coating/insulator interface, which spontaneously breaks symmetry and thereby induces superconductivity.

Given that the superconducting charge carriers are electrons, with a number density of superconducting charge carriers on the order of ten to the twentieth per cubic centimetre (endemic of unconventional superconductors such as Yttrium Barium Copper Oxide or YBCO), the London penetration depth, and hence the thickness of the coating of the wire, is on the order of micron(s). However, this thickness could be much greater, if practicable.

Consider an experimental set-up at standard room temperature and pressure, where a current carrying Al-coated wire (in a cylindrical configuration) is mechanically vibrated in an abrupt/accelerated manner by being struck with a non-conductive element, such as a Teflon pick, in order to generate accelerated vibrations. A more effective means of vibrating a wire in tension is by use of an electromagnetic (EM) plucking coil located in close proximity to the wire. However, this EM method of vibration may not be conducive to RTSC, since the mechanically-plucked Al-coated composite wire may fail the Meissner effect test for superconductivity, and not be able to expel the flux lines of the externally applied magnetic field. Further consider the electrically-driven vibration version of this idea, whereby a non-Al coated wire coated with lead zirconate titanate (PZT) is abruptly vibrated by having an electrical potential difference applied along its PZT coating, thus inducing wire vibration via the piezoelectric effect. Moreover, it has been shown that micrometer-size PZT thin film deposits can excite high vibration frequencies, exceeding 100 MHz, which would generate high EM fluxes in an outward direction, from the surface of the current-carrying composite wire. This method of vibration would be greatly conducive to superconductivity, since enablement of the Meissner effect would be possible.

There are three characteristics that a material must possess in order to be superconductive, a state of matter which constitutes a macroscopic quantum phenomenon. The three characteristics are perfect diamagnetism (the Meissner effect), perfect electrical conductivity (zero electrical resistance), and macroscopic quantum coherence. Considering that the current carrying wire is abruptly vibrated by mechanical or piezoelectric means, this will generate a magnetic field which would exclude (expel) the magnetic field lines of an externally applied magnetic field, thus enabling a condition of perfect diamagnetism (exhibiting the Meissner effect), thus the present invention meets the first requirement for superconductivity.

For the vibrated wire, the condition for the Meissner effect to occur is expressed as an inequality: the permeability of free space times the current divided by two pi times the wire radius, added to the permeability of free space times the wire surface charge density times the accelerated vibration amplitude times the square of the accelerated vibration frequency times the total vibration interval, must be greater than or equal to the maximum magnetic induction from an externally applied magnetic field. Note that this equation is not a function of temperature and thus not a function of the critical temperature below which the wire becomes superconductive, thus the condition for the Meissner effect (perfect diamagnetism) becomes possible at room temperature. It is important to also note that the main driving parameter in this expression is the accelerated vibration frequency, which solely exhibits a second power (non-linear) term.

In the present invention, since only the coating of the wire carries a charge due to the current, in the insulator core or wire bulk, there is no charge motion. This means that the magnetic induction within the insulator core or wire bulk is zero, hence the time rate of change of the induction is zero as well (the two conditions for deriving the London equation describing the superconducting state, from the Maxwell equations). From Faraday's law we obtain that the curl of the electric field under that condition is zero. Combining this result with the form of Ohm's law relating electric field strength with the product of current density and electrical resistivity (time independent), it can be shown that the electric field must be zero (since we have current) only under the condition of zero electrical resistivity, hence perfect electrical conductivity. Thus, the present invention meets the second requirement for superconductivity mentioned above.

The third requirement for superconductivity, namely the enablement of macroscopic quantum coherence, is best described by the conventional BCS (Bardeen, Cooper, and Schrieffer) theory. As the current courses along the wire, particularly along the coating, the lattice ionic vibrations (electron-phonon interactions) will create an attractive force between electrons (of opposite spins and opposite momentum), which normally want to repel one another, due to Coulomb repulsion. Thus, electron pairs, named Cooper pairs, will be formed, which will subsequently condense into a single quantum mechanical state, represented by a unique wave function. In the present invention, under room temperature conditions, the thermal agitations (fluctuations)-induced lattice vibrations will couple with the artificially induced (by purely mechanical or piezoelectric means) vibrations of the lattice ions, produced by the abrupt (accelerated) vibration of the wire, to generate a virtual 'soup' of fluctuations, a highly non-linear, far-from-equilibrium environment in the coating of the wire.

The complex interactions between a physical system and its surroundings (environment), disrupt the quantum mechanical nature of a system and render it classical under ordinary observation. This process is known as decoherence. However, it is argued that we can retard (delay) decoherence (and possibly even suppress it — namely decouple a physical system from the environment) by accelerated spin and/or accelerated vibration of electrically charged matter under rapid acceleration transients. This may be the very condition to achieve a state of macroscopic quantum coherence, the idea being that we never let the system achieve thermodynamic equilibrium, by constantly delaying the onset of relaxation to equilibrium (hence the production of maximal entropy is delayed). The system may "violently" react by generating "anomalous" emergent phenomena, such as room temperature superconductivity.

The Prigogine effect as discussed in a peer-reviewed published paper by the inventor, "The high energy electromagnetic field generator" published in Int. J. Space Science and Engineering, Vol. 3, No. 4, 2015 pp. 312-317, teaches us that under three conditions, a chaotic system (the aforementioned 'soup' of fluctuations) can self-organize into an orderly state, equivalent to the state of macroscopic quantum coherence. These conditions are the existence of a highly non-linear medium, an abrupt departure far-from-thermodynamic equilibrium, and an energy flux (caused by the intermittent abrupt vibration of the wire) to maintain the process of self-organization (order from chaos). This shows that the present invention has macroscopic quantum coherence, fulfilling the final requirement for superconductivity.

It is possible that the key to superconductivity (and especially RTSC) is the enablement of local macroscopic quantum coherence, namely the ability of a macroscopic object to act as if quantum mechanical in nature exhibiting such phenomena as superposition, entanglement, tunneling. In summary, one can argue that the synthesis of three physical mechanisms, namely the Meissner effect, the Cooper effect (or bipolaron formation), and the Prigogine effect leads directly to the possibility of room temperature superconductivity, at least in a special composite metal wire.

To buttress our argument from an experimental perspective, a recently published paper by M. Mitrano et al., entitled "Possible light-induced superconductivity in K3C60 at high temperature" published in Nature 530, 461-464, on 25 Feb. 2016, shows that "by exciting metallic K3C60 (potassium doped fullerene) with mid-infrared optical pulses, we induce a large increase in carrier mobility, accompanied by the opening of a gap in the optical conductivity"; thus showing the importance of non-equilibrium phenomena in effecting high Tc superconductivity.

Claims

What is claimed is:

1. A room temperature superconductor comprising: a wire comprising an insulator core and a metal coating, the metal coating disposed around the insulator core, the metal coating deposited on the core, and, when a pulsed current is passed through the wire while the wire is vibrated, room temperature superconductivity is induced.

2. A piezoelectricity-induced room temperature superconductor comprising: a wire comprising an insulator core and a PZT coating, the PZT coating disposed around the insulator core, the PZT coating deposited on the core, the PZT coating undergoes polarizing treatment after deposition, and, when a pulsed current is passed through the wire, room temperature superconductivity is induced.

3. The superconductor of claim 2, wherein the PZT coating is deposited on the core by vacuum evaporation.

4. The superconductor of claim 2, wherein the coating has a thickness on the order of the London penetration depth.

5. The superconductor of claim 1, wherein the wire coating is a material in which the piezoelectric effect can be induced.

6. The superconductor of claim 1, wherein the superconductor further comprises an electromagnetic coil, the electromagnetic coil circumferentially positioned around the metal coating, such that when the electromagnetic coil is activated, a non-linear vibration of the superconductor is induced, enabling room temperature superconductivity.

7. The superconductor of claim 1, wherein the coating is aluminum.

8. The superconductor of claim 1, wherein the coating has a thickness on the order of the London penetration depth.