Memristor – charge produced by a quantum size effect?

Jan. 14, 2011 - PRLog -- Background

The memristor is a nanoscale thin film that remembers the amount of current that has passed through it. Hence, the memristor behavior depends on the time integral of current - otherwise called charge. When current flows through the memristor, the resistance increases, but when current flows in the opposite direction, the resistance decreases. If the current is stopped, the memristor remembers the amount of current that has passed through it.  See http://en.wikipedia.org/wiki/Memristor

Attempts to understand how charge is produced in the memristor behavior have focused on the movement of oxygen vacancies and charged defects in oxide barriers. Stan Williams of HP Labs reports the actual resistance of the titanium dioxide memristors changes depending on the amount of voltage and the time the voltage has been applied. Williams says it is only at the nanoscale that the behavior of the memristor is detectable. At macroscopic sizes, the memristors behave like ordinary resistors, where resistance is equal to the voltage divided by the current. Ibid

Historically, electronics was developed at the macroscale. Leon Chua, who first postulated the existence of memristors in a 1971, gives the difficulty in producing nanoscale films as the reason why memristors remained dormant untill now. However, Williams found the Chua’s mathematics underlying memristor behavior not simple, but Chua says that he is pleased that his theory has finally been proved. See http://www.blindnero.com/forums/phpBB3/viewtopic.php?f=8&...

However, memristors are not limited to thin titanium dioxide films. Indeed, 20 nm clusters of bismuth showing memristor behavior that do not depend on charged defects and oxygen vacancies suggest a percolation-tunneling mechanism is at play. See http://www.phys.canterbury.ac.nz/research/nano/Percolatio...

Quantum Mechanics

Contrary to current explanations of  memristor behavior, the source of charge in nanoscale thin films is the size effect of  quantum mechanics (QM). Classical physics in macroscopic structures requires temperature increases to conserve absorbed EM energy. QM differs in that absorbed EM energy of any form cannot be conserved by an increase in temperature because the atom lacks heat capacity at the nanoscale, i.e. the specific heat vanishes. See http://www.nanoqed.org, “Specific Heat in Nanostructures,” 2010

Conservation of absorbed EM energy in nanoscale thin films and clusters therefore proceeds by the QED induced creation of photons by frequency up-conversion of the absorbed EM energy to the TIR resonant frequency of the nanostructure, typically beyond the UV. QED stands for quantum electrodynamics, TIR for total internal reflection, and UV for ultraviolet. The QED photons created inside the nanostructure having high Planck energy beyond the UV are sufficient to spontaneously produce charge by the photoelectric effect. At the nanoscale, the TIR confinement of QED photons is significant because of the high surface to volume ratio, but is only momentary. Indeed, the QED photons eventually escape TIR confinement if they are reoriented upon collisions with atoms to near normal incidence with the surface. See Ibid, 2010 in general and specifically charging of nanostructures in “Nanocars by Quantum Mechanics”, 2010

QM  and Memristor Behavior

The QM effect in memristors is caused by the EM energy in the form of electrical power P(t) which may be expressed as  P(t) =  V(t)*I(t) = R(t)*I(t)^2, where V(t) is the voltage, I(t) is the current, R(t) is the resistance, and t is time. By QM, P(t) is converted to QED photons inside the memristor that by the photoelectric effect produce charge q(t) and free electrons inside the memristor. Since P(t) is independent of the direction of  I(t), the q(t) is always being produced, at least until charge build-up stops the current flow. Charges are attracted to the negative V(t) terminals while free electrons are attracted to the positive V(t). Therefore, charge q(t) build-up may cause the current to decrease and stop. R(t) is always positive, but can increase or decrease depending on the q(t) level in the memristor.

Conclusions

1.  The charging of memristors most likely has nothing to do with the movement of oxygen vacancies and defects or percolation-tunneling.

2.  Memristor charge is a QM size effect caused by supplying EM energy in the form of electrical power to the memristor that cannot be conserved by an increase in temperature.

3.  Absorbed EM energy is conserved by producing QED photons in the TIR confinement of the nanostructure. The QED photons are typically beyond the UV having the Planck energy  to produce the observed charge within the memristor by the photoelectric effect.

4.  In macroscopic structures, the QED photons are also produced, but at the TIR resonance in the far IR the QED photons lack the Planck energy to create charge and free electrons by the photoelectric effect.

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About QED Indcued EM Radiation: Classically, absorbed EM energy is conserved by an increase in temperature. But at the nanoscale, temperature increases are forbidden by quantum mechanics. QED radiation explains how absorbed EM energy is conserved at the nanoscale by the emission of nonthermal EM radiation