I recently learned some new things about quantum materials, states, and computing.
My latest discoveries about the curious world of quantum physics and discoveries that may significantly impact the future.
Category: quantum physics – Page 465
This Physicist Says Electrons Spin in Quantum Physics After All. Here’s Why
‘Spin’ is a fundamental quality of fundamental particles like the electron, invoking images of a tiny sphere revolving rapidly on its axis like a planet in a shrunken solar system.
Only it isn’t. It can’t. For one thing, electrons aren’t spheres of matter but points described by the mathematics of probability.
But California Institute of Technology philosopher of physics Charles T. Sebens argues such a particle-based approach to one of the most accurate theories in physics might be misleading us.
Collision review: How CERN’s stellar secrets became sci-fi gold
Edited by Rob Appleby and Connie Potter (Comma Press)
IN The Ogre, the Monk and the Maiden, Margaret Drabble’s ingenious story for the new sci-fi anthology Collision, a character called Jaz works on “the interface of language and quantum physics”. Jaz’s speciality is “the speaking of the inexpressible”. Science fiction authors have long grappled with translating cutting-edge research – much of it grounded in what Drabble calls “the Esperanto of Equations” – into everyday language and engaging plots.
The Many Worlds of Quantum Mechanics
Sean Carroll CalTech, John’s Hopkins, Santa Fe Institute One of the great intellectual achievements of the twentieth century was the theory of quantum mech…
No ‘second law of entanglement’ after all, claims study
The second law of thermodynamics is often considered to be one of only a few physical laws that is absolutely and unquestionably true. The law states that the amount of ‘entropy’—a physical property—of any closed system can never decrease. It adds an ‘arrow of time’ to everyday occurrences, determining which processes are reversible and which are not. It explains why an ice cube placed on a hot stove will always melt, and why compressed gas will always fly out of its container (and never back in) when a valve is opened to the atmosphere.
Only states of equal entropy and energy can be reversibly converted from one to the other. This reversibility condition led to the discovery of thermodynamic processes such as the (idealized) Carnot cycle, which poses an upper limit to how efficiently one can convert heat into work, or the other way around, by cycling a closed system through different temperatures and pressures. Our understanding of this process underpinned the rapid economic development during the Western Industrial Revolution.
The beauty of the second law of thermodynamics is its applicability to any macroscopic system, regardless of the microscopic details. In quantum systems, one of these details may be entanglement: a quantum connection that makes separated components of the system share properties. Intriguingly, quantum entanglement shares many profound similarities with thermodynamics, even though quantum systems are mostly studied in the microscopic regime.
Study achieves the coherent manipulation of electron spins in silicon
In recent years, many physicists and computer scientists have been working on the development of quantum computing technologies. These technologies are based on qubits, the basic units of quantum information.
In contrast with classical bits, which have a value of 0 or 1, qubits can exist in superposition states, so they can have a value of 0 and 1 simultaneously. Qubits can be made of different physical systems, including electrons, nuclear spins (i.e., the spin state of a nucleus), photons, and superconducting circuits.
Electron spins confined in silicon quantum dots (i.e., tiny silicon-based structures) have shown particular promise as qubits, particularly due to their long coherence times, high gate fidelities and compatibility with existing semiconductor manufacturing methods. Coherently controlling multiple electron spin states, however, can be challenging.