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Quantum Mechanics and Nanoelectronics Thomas Prevenslik QED Radiations Discovery Bay, Hong Kong 1 ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 Introduction Nanoelectronics became popularized by Chua in 1971 claiming [1] a circuit element existed having a resistance that depended on the time–integral of the current. Based on symmetry arguments, electronics based on the resistor, capacitor, and inductor was considered incomplete. For completeness, Chua proposed a fourth element: Memristor [1] L. O. Chua, “Memristor - the missing circuit element,” IEEE Trans. Circuit Theory, vol. 18, pp. 507–519, 1971. ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 2 Background Chua lacked a working prototype, and the memristor lay dormant for almost 40 years In 2008, a group at Hewlett-Packard (HP) developed [2] a memristor comprising a thin film of TiO2 sandwiched between Pt electrodes. 2. D. B. Strukov, et al., “The missing memristor found,” Nature 453, 7191 (2008). 3 ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 HP Memristor The memristor is basically a variable resistor dependent on the current I that flows by the amount of charge Q transferred. Q = I dt HP claims the charge is caused by oxygen vacancies in the TiO2 that act as positive charge holes moving under the bias voltage that change the memristor resistance during the cycle 4 ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 Problem Memristor behavior is found without oxygen vacancies in molecular layers between gold electrodes and in single materials without electrodes, e.g., silicon nanowires Lacking vacancies, explanations of memristor behavior assume the presence of space charge, but the mechanism by which the space charge is produced is not identified. 5 ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 Observations Memristor behavior only observed at the nanoscale. (Thin films, nanowire, etc) At the macroscale, memristors behave like ordinary resistors where resistance is voltage divided by current. The observations suggest a QM size effect QM = Quantum Mechanics ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 6 Space Charge In this talk I will convince you that QM creates charge Q anytime EM energy is absorbed at the nanoscale For memristors, the EM energy is Joule heating. But QM requires the heat capacity of the thin film to vanish so the Joule heat cannot be conserved by an increase in temperature. Instead, conservation proceeds by the QED induced creation of QED photons inside the film, the QED photons creating charge Q by Einstein’s photoelectric effect. QED = Quantum Electrodynamics 7 ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 Memristor Geometry D + QED Radiation D t t d d - t + QED Radiation L - t I I Thin Film I Nanowire 8 ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 Proposal The charge in nanoelectronic circuit elements is a QM effect caused by photolysis from QED radiation created from the conservation of Joule heat that otherwise is conserved by an increase in temperature. At the nanoscale, QM creates charge instead of the classical increase in temperature 9 ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 Heat Capacity of the Atom Classical Physics (kT > 0) QM (kT = 0) hc E hc exp kT 1 kT 0.0258 eV Nanostructures In nanostructures, QM requires atoms to have zero heat capacity ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 10 Conservation of Energy Lack of heat capacity by QM precludes Joule heat conservation in memristors by an increase in temperature, but how does conservation proceed? Conservation Proposal Generally, absorbed EM energy is conserved by creating QED photons inside the nanostructure - by frequency up or down conversion to the TIR resonance of the nanostructure. TIR = Total Internal Reflection Up-conversion produces high energy QED photons in memristors, but down-conversion also occurs, e.g., redshift of galaxy light in dust in the 2011 Nobel in physics on an expanding Universe ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 11 TIR Confinement Since the refractive index of the memristor is greater than that of the surroundings, the QED photons are confined by TIR (Tyndall 1870) Memristors ( films, wires) have high surface to volume ratio, but why important? Propose EM energy absorbed in the surface of memristors provides the TIR confinement of the QED photons. Since the QED photons have wave functions that vanish normal to the surface, QED photons are spontaneously created by Joule heat dissipated in memristors f = c/ = 2nd (or 2nD) E = hf ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 12 QED Heat Transfer QQED is non-thermal radiation at TIR frequency QED Photons Currently, K < Bulk in thin films is explained by scattering of phonons, but if QQED is included in heat balance, then K = Bulk Phonons QED Radiation 13 ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 QED Photons and Excitons QED Photon Rate P = Joule heat E = QED Photon energy = Absorbed Fraction Exciton Rate Y = Yield of Excitons / QED Photon 14 ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 Exciton Response Electrons Holes Where, QE and QH are number electrons and holes, F is the field, and E and H are electron and hole mobility Taking F = Vo sin t / d, Solution by Integrating factor gives 15 ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 Resistance and Current = Conductivity = Resistivity 16 ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 Simulation R I d = 50 nm , f = 5 kHz, and Vo = 1 V Ro = 100 and P = 10 mW H = 2x10-6 cm2/V-s ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 17 Hysteresis Curve 18 ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, Conclusions Modern day electronics was developed for the macroscale, but a QM approach is suggested at the nanoscale where memristive effects are observed. Memristive effects in PCRAM films by melting are negated by QM. Ovshinsky’s redistribution of charge carriers by QM is more likely. Memristors have nothing to do with the notion of the missing fourth element necessary for completeness. Memristor behavior is simply a QM size effect. 19 ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 Expanding Unverse In 1929, Hubble measured the redshift of galaxy light that by the Doppler Effect showed the Universe is expanding. But cosmic dust of submicron NPs permeate space and redshift galaxy light without Universe expansion 20 ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 Redshift in Cosmic Dust Based on classical physics, astronomers assume absorbed galaxy photon increases temperature of dust NPs Galaxy Photon Dust o = 2nD > Redshift Photon o Redshift without Universe expansion ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 21 Nobel Mistake Astronomers Schmidt, Pearlmutter, and Reiss got the 2011 Nobel in Physics for an accelerated expanding Universe Referring to his calculation showing acccelerated Universe expansion, Reiss is quoted as saying: "I remember thinking, I've made a terrible mistake and I have to find this mistake" Others said: “[Riess] did a lot after the initial result to show that there was no sneaky effect due to dust absorption“ Reiss did make a mistake - Redshift does occur in dust No Universe expansion, accelerated or otherwise 22 ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011 Questions & Papers Email: [email protected] http://www.nanoqed.org 23 ICMON 2011 : Inter.l Conf. Micro, Opto, Nanoelectronics, Venice, Nov. 28-30, 2011