Posted Content•
Persistent Currents in Normal Metal Rings (Yale PhD thesis)
TL;DR: In this article, the typical persistent current (the component that varies randomly from ring to ring) was measured with high sensitivity, over two orders of magnitude smaller than that observed in previous studies.
Abstract: In this work, I present measurements of persistent currents in normal metal rings performed with cantilever torsional magnetometry. With this technique, the typical persistent current (the component that varies randomly from ring to ring) was measured with high sensitivity. I report measured magnitudes as low as 1 pA, over two orders of magnitude smaller than that observed in previous studies. These measurements extend the range of temperature and magnetic field over which the typical current has been observed. The wide magnetic field range allowed us to study the effect of magnetic field penetrating the ring. It also enabled the recording of many independent measurements of the current magnitude in a single sample. These independent measurements are necessary to characterize the persistent current magnitude because it is a random quantity. From these measurements of the persistent current, I also characterize the parametric dependence of the typical current on sample orientation and number of rings. In addition to presenting the experimental results, I thoroughly review the theory of the typical persistent current in the diffusive regime. I begin with the simplest model and build up to the case appropriate for the samples studied in our experiments. I also present in detail the experimental apparatus used to measure the persistent currents.
Citations
More filters
Journal Article•
TL;DR: The combined use of ultrasensitive magnetic resonance force microscopy (MRFM) with 3D image reconstruction to achieve magnetic resonance imaging (MRI) with resolution <10 nm demonstrates the potential of MRFM as a tool for 3D, elementally selective imaging on the nanometer scale.
Abstract: We have combined ultrasensitive magnetic resonance force microscopy (MRFM) with 3D image reconstruction to achieve magnetic resonance imaging (MRI) with resolution <10 nm. The image reconstruction converts measured magnetic force data into a 3D map of nuclear spin density, taking advantage of the unique characteristics of the “resonant slice” that is projected outward from a nanoscale magnetic tip. The basic principles are demonstrated by imaging the 1H spin density within individual tobacco mosaic virus particles sitting on a nanometer-thick layer of adsorbed hydrocarbons. This result, which represents a 100 million-fold improvement in volume resolution over conventional MRI, demonstrates the potential of MRFM as a tool for 3D, elementally selective imaging on the nanometer scale.
402 citations
TL;DR: In this article, the Dirac Delta Function has been used to model the relationship between stress and strain in two-dimensional lattices and elasticity relations in a three-dimensional manifold.
Abstract: 1 Introduction: Linear Atomic Chains- 2 Two- and Three-Dimensional Lattices- 3 Properties of the Phonon Gas- 4 Stress and Strain- 5 Elasticity Relations- 6 Static Deformations of Solids- 7 Dynamical Behavior of Solids- 8 Dissipation and Noise in Mechanical Systems- 9 Experimental Nanostructures- 10 Nanostructure Fabrication I- 11 Nanostructure Fabrication II- A Mathematical Tools- A1 Scalars, Vectors, Tensors- A11 Vectors- A12 Tensors- A2 Eigenvectors and Eigenvalues- A3 The Dirac Delta Function- B Compatibility Relations for Stress and Strain- C Notation
182 citations
01 Mar 2004
TL;DR: By coupling a single-electron transistor to a high–quality factor, 19.7-megahertz nanomechanical resonator, position detection approaching that set by the Heisenberg uncertainty principle limit is demonstrated and the near-ideal performance of the single-Electron transistor as a linear amplifier is demonstrated.
Abstract: By coupling a single-electron transistor to a high–quality factor, 19.7-megahertz nanomechanical resonator, we demonstrate position detection approaching that set by the Heisenberg uncertainty principle limit. At millikelvin temperatures, position resolution a factor of 4.3 above the quantum limit is achieved and demonstrates the near-ideal performance of the single-electron transistor as a linear amplifier. We have observed the resonator's thermal motion at temperatures as low as 56 millikelvin, with quantum occupation factors of NTH = 58. The implications of this experiment reach from the ultimate limits of force microscopy to qubit readout for quantum information devices.
39 citations
TL;DR: In this article, the magnetic quantum periodicity in the dc voltage is observed when asymmetric rings are switched between superconducting and normal state by a noise or ac current, which is used for detection of a non-equilibrium noise with the help of a system of 667 asymmetric aluminum rings of $1 \ \mu m$ in diameter connected in series.
Abstract: Magnetic quantum periodicity in the dc voltage is observed when asymmetric rings are switched between superconducting and normal state by a noise or ac current. This quantum effect is used for detection of a non-equilibrium noise with the help of a system of 667 asymmetric aluminum rings of $1 \ \mu m$ in diameter connected in series. Any noise down to the equilibrium one can be detected with the help of such system with enough great number of asymmetric rings.
9 citations
Posted Content•
TL;DR: In this article, the authors reveal incompleteness and inconsistency in the description of quantum phenomena and reveal that quantum phenomena can be explained by quantum mechanics. But impartial consideration uncovers the incomteness of this description.
Abstract: Canonical description of quantization effects observed at measurements on superconducting structures seems one of the most triumphant achievements of quantum mechanics. But impartial consideration uncovers incompleteness and inconsistency of this description. Contradictions in the description of other quantum phenomena are revealed also.
5 citations
Cites background from "Persistent Currents in Normal Metal..."
...But the persistent current does not decay in resistive rings [8, 9, 19, 22, 23]....
[...]
...The authors [22, 40] claim that this equilibrium current flowing through a resistive circuit is dissipationless....
[...]
...The ’quantum force’ was introduced in [30] for the description of other paradox, observed both in the fluctuation region of superconducting rings [8, 9, 19] and normal metal rings [22, 23]....
[...]
...Thus, Bohr’s quantization (1) and the influence of the magnetic vector potential A on the phase ∇φ of the wave function (call sometimes as Aharonov-Bohm effect [21]) seem to describe successfully numerous quantum phenomena observed in superconducting rings and also in normal metal mesoscopic rings [22, 23]....
[...]
References
More filters
TL;DR: In this paper, a new method for analysing nonlinear and nonstationary data has been developed, which is the key part of the method is the empirical mode decomposition method with which any complicated data set can be decoded.
Abstract: A new method for analysing nonlinear and non-stationary data has been developed. The key part of the method is the empirical mode decomposition method with which any complicated data set can be dec...
18,956 citations
TL;DR: The atomic force microscope as mentioned in this paper is a combination of the principles of the scanning tunneling microscope and the stylus profilometer, which was proposed as a method to measure forces as small as 10-18 N. As one application for this concept, they introduce a new type of microscope capable of investigating surfaces of insulators on an atomic scale.
Abstract: The scanning tunneling microscope is proposed as a method to measure forces as small as 10-18 N. As one application for this concept, we introduce a new type of microscope capable of investigating surfaces of insulators on an atomic scale. The atomic force microscope is a combination of the principles of the scanning tunneling microscope and the stylus profilometer. It incorporates a probe that does not damage the surface. Our preliminary results in air demonstrate a lateral resolution of 30 A and a vertical resolution less than 1 A.
12,344 citations
TL;DR: In this article, a theory of superconductivity is presented, based on the fact that the interaction between electrons resulting from virtual exchange of phonons is attractive when the energy difference between the electrons states involved is less than the phonon energy, and it is favorable to form a superconducting phase when this attractive interaction dominates the repulsive screened Coulomb interaction.
Abstract: A theory of superconductivity is presented, based on the fact that the interaction between electrons resulting from virtual exchange of phonons is attractive when the energy difference between the electrons states involved is less than the phonon energy, $\ensuremath{\hbar}\ensuremath{\omega}$. It is favorable to form a superconducting phase when this attractive interaction dominates the repulsive screened Coulomb interaction. The normal phase is described by the Bloch individual-particle model. The ground state of a superconductor, formed from a linear combination of normal state configurations in which electrons are virtually excited in pairs of opposite spin and momentum, is lower in energy than the normal state by amount proportional to an average ${(\ensuremath{\hbar}\ensuremath{\omega})}^{2}$, consistent with the isotope effect. A mutually orthogonal set of excited states in one-to-one correspondence with those of the normal phase is obtained by specifying occupation of certain Bloch states and by using the rest to form a linear combination of virtual pair configurations. The theory yields a second-order phase transition and a Meissner effect in the form suggested by Pippard. Calculated values of specific heats and penetration depths and their temperature variation are in good agreement with experiment. There is an energy gap for individual-particle excitations which decreases from about $3.5k{T}_{c}$ at $T=0\ifmmode^\circ\else\textdegree\fi{}$K to zero at ${T}_{c}$. Tables of matrix elements of single-particle operators between the excited-state superconducting wave functions, useful for perturbation expansions and calculations of transition probabilities, are given.
9,619 citations
Book•
01 Jan 1966
TL;DR: In this article, the authors present a model for vector analysis based on the Calculus of Variations and the Sturm-Liouville theory, which includes the following: Curved Coordinates, Tensors.
Abstract: Vector Analysis. Curved Coordinates, Tensors. Determinants and Matrices. Group Theory. Infinite Series. Functions of a Complex Variable I. Functions of a Complex Variable II. Differential Equations. Sturm-Liouville Theory. Gamma-Factrial Function. Bessel Functions. Legendre Functions. Special Functions. Fourier Series. Integral Transforms. Integral Equations. Calculus of Variations. Nonlinear Methods and Chaos.
7,811 citations
Book•
01 Jan 1975
TL;DR: In this article, a revised version of the book has been published to incorporate the many new developments in superconductivity, including new topics on high temperature superconductors and nonequilibrium superconductivities.
Abstract: Appropriate for intermediate or advanced courses in superconductivity, this edition has been revised to incorporate the many new developments in superconductivity. Expanded topic coverage includes new chapters on high temperature superconductors and nonequilibrium superconductivity.
7,800 citations
"Persistent Currents in Normal Metal..." refers background or methods in this paper
...where h is Planck’s constant and kB is the Boltzmann constant [300]....
[...]
...We analyze the measurements of the superconducting state using the Ginzburg-Landau theory for superconductivity [300]....
[...]
...In the presence of a static magnetic field, a bulk superconductor develops surface currents which screen the magnetic field from the superconductor’s interior, a phenomenon known as the Meissner effect [300]....
[...]
...The cases of a one dimensional ring [300] and a ring with finite linewidth [200] in a magnetic field perpendicular to the ring plane have been considered previously....
[...]
...where Te is the temperature of the superconductor and Tc is the superconducting transition temperature in the absence of an applied magnetic field [300, 302]....
[...]