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Attosecond-Scale Research Elucidates Dynamics of Spin-Dependent Quantum Tunneling Through Chiral Molecules

Experiments directly on tunneling ionization dynamics have discovered that electrons will behave differently when quantum tunneling from a molecule depending on the molecule's chirality (chirality refers to the “handedness” of non-superimposable stereoisomers of a molecule, the same way a left hand cannot be superimposed over a right hand, even though they are mirror images of each other). The projection of electron spin onto its momentum direction, called spin-orbit coupling, strongly affects the tunneling probability between chiral molecules of the biological system. This phenomenon of electron conduction being enhanced by an electron’s spin orientation is known as chiral-induced spin selectivity (CISS). Previous studies had shown that the helical geometry found in many biomolecules, like DNA and alpha helices of proteins, induces robust spin filtering accompanied by, and intimately related to, strongly enhanced transmission, and now new research investigating...

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Neutron Helical Waves

CREDIT: SEAN KELLEY/NIST 


By Amal Pushp, Affiliate Physicist at the Resonance Science Foundation 

Neutrons form a major component of baryonic matter. Except for hydrogen, neutrons are present in the central region (nucleus) of the atoms of all elements. Although they are electrically neutral, they are very crucial for the determination of atomic structure and its composition. One of the key reasons why they are influential is due to the fact that they can penetrate materials that optical radiations like X-rays usually cannot. 

The de Broglie hypothesis of quantum theory tells us that elementary particles can possess dual characteristics, wave and particle, depending on the situation. Just like the electrons, the wave characteristics of neutrons can also be employed to study materials and one of the major advantages in this regard is that the wavelength can be turned extremely small which in turn results in a high-resolution image of the sample under study. This...

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Anomalous Hall effect in Antiferromagnetic Crystal May Enable Computation with Atomic Spin

By: William Brown, Biophysicist at the Resonance Science Foundation

Digital Computations are based on the ability to read, write, and erase an on/off state in a material, representing the ‘0’ and ‘1’ of binary data. In today’s integrated circuits, this is achieved via transistors, which are semiconductor materials— like silicon or germanium (tetrahedral elements)— that can switch electrical signals to an “on” or “off” state and therefore function as the binary state, or logic gate in a digital computation.

In this way, the metal-oxide-silicon transistors in integrated circuits forms the memory cells of the chips, and because of the relative ease of fabrication, scalability, and low-power consumption such chips are found in nearly all digital electronic devices, from smartphones to TVs. The civilization-scale effect of this functional material with easily controlled binary state cannot be overstated, as even...

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Ionization of Gravitational Atoms

By: William Brown, Biophysicist at the Resonance Science Foundation

Stellar mass black holes, like elementary particles, are remarkably simple objects. They have three primary observable properties: mass, spin, and electric charge. The similarities with elementary particles, like the proton, doesn’t stop there, as stellar mass black holes in binary systems can also form bound and unbound states due to interaction of orbital clouds (from boson condensates), uncannily analogous to the behavior and properties of atoms.  

The spin of stellar mass black holes is a particularly significant property, as black holes have rapid rotations that generate a region of space called the ergosphere around the event horizon, where the torque on spacetime is so great that an object would have to travel at a velocity exceeding the speed of light just to stay in a stationary orbit. Analysis of this region has resulted in some interesting physics predictions, one being the phenomenon of...

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Quantum Simulator Reveals New State of Matter Possible with Topological Spin Liquids

By Resonance Science Foundation biophysicist William Brown

Quantum spin liquids are exotic phases of matter that offer potential applications in robust quantum information processing with topological qubits. Quantum spin liquids are a phase of matter that feature long-range quantum entanglement involving the magnetic dipoles, or spin, of electrons. Unlike in conventional magnets where the magnetic dipoles of electrons all align and freeze into place, electrons in this new exotic phase are constantly changing and fluctuating like a liquid— leading to one of the most entangled states of matter ever conceived. 

Until recent investigations it was unknown if such a highly quantum correlated magnetic state could be realized in an actual physical system. Now, using a 219-atom programmable quantum simulator a team of Harvard researchers have shown that quantum matter and protected quantum information processing are possible with topological spin liquids. Their findings...

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