Science & Technology - Posted by Kitta MacPherson-Princeton on Wednesday, February 10, 2010 11:22 - 1 Comment
Waves of electrons on the verge

On the brink of the metal-insulator transition, the electrons in a manganese-doped gallium arsenide semiconductor are distributed across the surface of the material in complex, fractal-like patterns. In this image, the fractal-like probability map of electrons is superimposed on the atomic crystal structure of the material, imaged at the same time. (Credit: Roushan/Yazdani Research Group)
PRINCETON (US)—For the first time, scientists have observed electrons in a semiconductor on the brink of transitioning from a metal to an insulator—a phenomenon shrouded in mystery despite decades of examination.
Caught in the act, the electrons formed complex patterns resembling those seen in turbulent fluids, confirming some long-held predictions and providing new insights into how semiconductors can be turned into magnets. The work, led by a team at Princeton University, also could lead to the production of smaller and more energy-efficient computers.
Details were published in the journal Science.
“The spatial structure of the electron waves inside a given material determines how well it conducts electricity,” says team leader Ali Yazdani, professor of physics. “If the waves extend throughout the material, we get metallic behavior, but if they get localized, or stuck, in specific regions, electricity stops flowing. The way in which electrons undergo this transition in certain semiconductors also appears to play a big role in how they become magnetic.”
In their natural state, semiconductors such as silicon or gallium arsenide are insulators that do not conduct electricity. For decades, scientists have known that they can transform these insulators into metals, which conduct electricity, by replacing some of the atoms in the chemical lattice structure with other atoms, for instance, replacing the gallium in gallium arsenide with zinc or manganese.
This process, called doping, changes the number of electrons in the material to enable the flow of electricity, but also introduces disorder into the lattice structure that can hinder the electrons’ movement and cause them to become “stuck,” or localized. Conduction is able to occur only if the electrons can “hop” from atom to atom in the structure, slaloming among the randomness and disorder where the lattice has been perturbed.
Yazdani’s team originally set out to understand how doping a gallium arsenide semiconductor with manganese atoms could convert it into a magnet and “turn on” electrical conductivity in the compound. After team members at the University of California-Santa Barbara added manganese atoms to the lattice structure, the researchers used specially designed scanning tunneling microscopes at Princeton to visualize the electron states in the material.
Finding themselves confronted with complex spatial patterns of electron waves, the scientists realized that the patterns they saw were in fact those predicted for electrons on the brink of localization. In these patterns, the majority of the electrons are distributed across the surface of the semiconductor in a series of interconnected “puddles” that resemble fractals—self-similar shapes that repeat themselves on increasingly smaller-length scales. Fractals commonly are associated with objects in nature, such as coastlines or snowflakes, but they have never before been seen for quantum particles.
These observed patterns have important implications for how a semiconductor becomes a magnet. All electrons have a property called “spin,” which describes the way they rotate on their axes, generating a magnetic field as they do so. If the spins of neighboring electrons in a given material are opposite one another, these magnetic fields cancel each other out.
But when the spins of neighboring electrons in a material are aligned, such that the electrons are rotating in tandem like synchronized swimmers in a pool, the material itself becomes magnetic. This alignment only occurs among the electrons of certain elements, including iron and manganese.
While it was assumed that magnetism in manganese-doped gallium arsenide occurs because the spins of all the manganese electrons in the doped semiconductor become aligned uniformly, the team’s results suggested this is not the case: The alignment of spins depended on the location of electrons within the fractal puddles, indicating that there are likely areas of strong and weak magnetic interaction in the material.
“We have shown that electrons move and live in these jagged puddles, so it is only natural to consider that manganese atoms that reside within each puddle are interacting with each other and giving rise to the magnetism,” Yazdani says. “In this view, where the puddles are not, we have manganese atoms but they are not interacting or contributing to magnetism. The puddles become part of the story to understand how magnetism comes about.”
Manganese-doped gallium arsenide has been at the heart of many recent technological advances, and a precise understanding of what causes magnetism in these semiconductors—and how to control it—will be necessary for the realization of one of the most promising applications of the material: computer chips able to both process and store information.
In current devices, chips made of semiconductors, such as silicon, are used to process information, which is then stored in hard drives made out of magnetic materials, such as iron. If the magnetism of a material could be switched on and off, the same chip could be used for both purposes, paving the way for smaller and more energy-efficient computers.
Researchers from the University of Illinois-Urbana/Champaign and the University of California-Santa Barbara contributed to the work, which was funded by the National Science Foundation, the Office of Naval Research, and the Army Research Office.
Princeton news: www.princeton.edu/main/news/



















The Electron… E Space
Space is broken up into geometrical patterns formed by the intersection of particles. These pieces of space contain their own individual and unique pressure, which exists within a spectrum.
Every particle which exists in “natural space,” the space that existed before the creation of the universe (altered space) and, which exists as infinite space outside of the universe, exists within a multitude of spectrums and are limited in mass and density.
In other words, particles can only be so small and so large and pressures can only be so great and so little. First, let’s examine the most massive particle that exists in space, the “macro particle” and all of its working parts. Like everything that exists in both natural and altered space, everything must adhere to the law of physics. Nothing can become too heavy nor can it become too large; if you put one too many bricks, the structure will collapse. The same principle applies to particles in space. In the case of space, its fluidity conforms to a natural configuration, just like water. Space is a sea of particles one linked to the other. These particles are pushed in all directions into one another as far as the pressure that opposes them will allow. “A macro particle” is a particle that exists in atomic space and so would be as small as what contemporary science calls an atom and can be as big as one half the size of the universe (altered space). These two massive particles that engulf the universe would be separated at the periphery and the center by a “quantum degree.” Quantum degree (qd) represents the smallest point in space, a space within a space. These qd’s form quantum structures that crisscross through space within which electrons flow. A “Quantum Structure” is a conduit within, which is contained pressure that is so intense, that it cannot become any greater “at the periphery” of the center. However, the pressure at the “center” of this structure is much less than the pressure at the periphery as one particle has been pushed through the center of another providing a space of “relative ambiance” at the very center. This space or Electron space (E. space) is broken up in the same way that natural space and altered space are broken up into particles that conform to the law of physics in relative pressure…electrons! This configuration of space at the greatest relative pressure provides the frequency signals that make matter what it is. The electrons flowing through these conduits in signature configurations are a computer program that makes this universe or altered space work. Matter is the final product of these signature configurations of electrons that vector up from the E. space. Matter is a chain reaction that begins with the Electron.
The electron conforms to the pressure that surrounds it on eight sides. Quantum conduits are octagonal at the center surrounded by four less octagonal larger particles at the periphery. Space is octagonal becoming less pronounced and more geometrically round as it vectors up to the limits of altered space until…one quantum degree at the periphery of the largest two macro particles is obtained.
Motion is a product of a natural imbalance that exists in space, an imbalance that takes us from the largest to the smallest. All structures in space reflect this imbalance. This imbalance causes particles within larger particles to be less dense at the periphery and most dense at the center. All particles are being pushed toward the center of a larger particle becoming denser as they move into the particle and eventually are pushed out of the center by larger more massive particles. This natural motion of particles from the periphery to center constitutes “particle orbit”.
Particle orbit amongst other things precludes the possibility of a big bang theory. All particles orbit in space! The heavier more massive particles at the periphery, push the particles of the greatest density toward the center… becoming smaller and denser themselves as they too move toward the center and then are pushed out of the center by bigger more massive particles and then back up again,” particle orbit”. Particle orbit is how space maintains homeostasis, a natural order. Space cannot be both static and fluid at the same time. The big bang theory could never have occurred because the particles at the center would never have come under the pressure necessary to form the universe in this way. Those particles would have simply been pushed from the center. When something in space becomes denser something else becomes less dense.
The electron can be defined as a quantum or even a sub quantum particle. It is the densest and smallest particle in the universe. Matter is defined as groups of electrons configured in signature patterns at the smallest level, vectoring up to atomic space in quantum structures!
These quantum structures contain the frequency signature for matter. Once contemporary science understands how to overcome the relative pressure of these structures and when we are able to expand or re- configure these electron clusters or signature frequencies (frequency transfer), science will have opened the door to quantum frequency transmission. This is the key to “other dimensional science”. Understanding electron space and the electron… is the key to opening these doors.
The words “other dimensional science” are misleading. I prefer to define space in terms of pressure or frequency spectrums and dimensional particles in terms of “particle signature density.” The door to other frequency spectrums does not unlock by” putting particles under extreme pressure in magnetic fields” but by putting pressure into quantum conduits and starting a chain reaction from the inside! The secret is… how do you produce that much relative pressure… relative pressure that is great enough to penetrate a quantum structure and enter E. space?