But IBM’s latest quantum chip and its competitors face a long path towards making the machines useful.
Magnetene could have useful applications as a lubricant in implantable devices or other micro-electro-mechanical systems.
A team of researchers from University of Toronto Engineering and Rice University have reported the first measurements of the ultra-low-friction behaviour of a material known as magnetene. The results point the way toward strategies for designing similar low-friction materials for use in a variety of fields, including tiny, implantable devices.
Magnetene is a 2D material, meaning it is composed of a single layer of atoms. In this respect, it is similar to graphene 0, a material that has been studied intensively for its unusual properties — including ultra-low friction — since its discovery in 2004.
A team of researchers from University of Toronto Engineering and Rice University have reported the first measurements of the ultra-low-friction behavior of a material known as magnetene. The results point the way toward strategies for designing similar low-friction materials for use in a variety of fields, including tiny, implantable devices.
The properties of a complex and exotic state of a quantum material can be predicted using a machine learning method created by a RIKEN researcher and a collaborator. This advance could aid the development of future quantum computers.
We have all faced the agonizing challenge of choosing between two equally good (or bad) options. This frustration is also felt by fundamental particles when they feel two competing forces in a special type of quantum system.
In some magnets, particle spins—visualized as the axis about which a particle rotates—are all forced to align, whereas in others they must alternate in direction. But in a small number of materials, these tendencies to align or counter-align compete, leading to so-called frustrated magnetism. This frustration means that the spin fluctuates between directions, even at absolute zero temperature where one would expect stability. This creates an exotic state of matter known as a quantum spin liquid.
Quantum theory is peerless at explaining reality, but assaults our intuitions of how reality should be. It seems likely the fault lies with our intuitions.
JILA researchers have tricked nature by tuning a dense quantum gas of atoms to make a congested “Fermi sea,” thus keeping atoms in a high-energy state, or excited, for about 10% longer than usual by delaying their normal return to the lowest-energy state. The technique might be used to improve quantum communication networks and atomic clocks.
Quantum systems such as atoms that are excited above their resting state naturally calm down, or decay, by releasing light in quantized portions called photons. This common process is evident in the glow of fireflies and emission from LEDs. The rate of decay can be engineered by modifying the environment or the internal properties of the atoms. Previous research has modified the electromagnetic environment; the new work focuses on the atoms.
The new JILA method relies on a rule of the quantum world known as the Pauli exclusion principle, which says identical fermions (a category of particles) can’t share the same quantum states at the same time. Therefore, if enough fermions are in a crowd—creating a Fermi sea—an excited fermion might not be able to fling out a photon as usual, because it would need to then recoil. That recoil could land it in the same quantum state of motion as one of its neighbors, which is forbidden due to a mechanism called Pauli blocking.
