A method that relies on hitting materials with neutrons can measure how much quantum entanglement hides within them, which could enable new kinds of quantum technology
Category: quantum physics
Selectively eliminating old, damaged fat cells
A team from The University of Texas at Austin reviews recent advances in dilute noble metal films for infrared optics and plasmonics: https://bit.ly/4s9XHKR
To address a growing need for a sub-wavelength and nanophotonic optical infrastructure to support quantum applications, dilute noble metals provide a high-optical-quality approach for nanophotonics at long wavelengths.
With further research, their potential applications can even include mid-IR sensing, optoelectronics, and quantum photonics at long wavelengths.
The infrared optical response of noble metals is traditionally considered perfect electrical conductor (PEC)-like due to the noble metals’ exceptionally large electron concentrations, and thus large (and negative) real permittivity. While PEC-like behavior is ideal for a broad range of applications, for instance mirrors, gratings, and wavelength-(and macro-) scale resonators and antennas, the utility of noble metals for nanoscale (sub-diffraction-limit) physics at long wavelengths is limited. However, in ultra-low volume (dilute) metal films, such as those with nanometer-scale thicknesses or lithographic dilution (subwavelength perforation), the thin films’ sheet conductivity is massively reduced, enabling light to penetrate and interact with the films much more efficiently. This avails the infrared of a host of opportunities for noble-metal-based plasmonics, with the potential for nanoscale (deep subwavelength) confinement and strong light-matter interaction, otherwise prohibited with noble metals in this wavelength range. In this perspective, we review the recent advances in dilute metal films for near-and mid-infrared photonics and plasmonics, and discuss the advantageous properties of these optical thin films for potential applications in sensors, detectors, sources, and nonlinear and quantum optics.
Avihu28/Quantum-Safe-Bitcoin-Transactions: A way to enable Quantum Safe Bitcoin transactions that is available today
The Cost: You don’t need a supercomputer to stay safe. A standard off-chain GPU and a few hundred dollars can “harden” your transaction against a multi-billion dollar quantum machine.
A way to enable Quantum Safe Bitcoin transactions that is available today. — avihu28/Quantum-Safe-Bitcoin-Transactions.
Optical control of nuclear spins in molecules points to new paths for quantum technologies
Researchers at the Karlsruhe Institute of Technology (KIT) have reported important progress in quantum physics and materials science by optically initializing, controlling, and reading out nuclear spin states in a molecular material for the first time. Because of their weak interaction with the environment, nuclear spins are particularly stable quantum information carriers. The research, published in Nature Materials, shows that molecular nuclear spins could be a promising building block for future quantum technologies.
Nuclear magnetic resonance (NMR) is an established method for analyzing materials and molecules, with applications ranging from chemical analysis to quantum information processing. For a new paper, KIT researchers analyzed a molecular crystal containing europium ions. Such ions have especially narrow optical transitions that allow direct addressing of nuclear spin states. Using laser light, they were able to initialize nuclear spins in defined states and then read out those states.
In addition to optical addressing, the researchers used high-frequency fields to control the spins and protect them from interfering environmental influences. They achieved nuclear spin quantum coherence with a lifetime of up to two milliseconds, an interval during which a quantum system maintains a precisely defined quantum mechanical state.
Robust against noise, geometric-phase swap gates bring stability to quantum operations
Researchers at ETH Zurich have realized particularly stable quantum logical operations with qubits made of neutral atoms. Since these operations, called quantum gates, are based on geometric phases, they are extremely robust against experimental noise and can be used in quantum computers in the future.
Quantum bits, or qubits, which are required for building quantum computers, come in different kinds. In recent years, many research institutes and companies have focused on superconducting circuits and trapped ions. However, neutral atoms trapped with laser light also have a lot going for them: since they carry no electric charge, they are less sensitive to disturbances. Moreover, trapping with laser light makes it easy to realize several thousand qubits in a single system—using superconductors or ions this is much more difficult.
Nevertheless, neutral atoms have their own problems. In quantum computers, qubits exist in superposition states of the logic values 0 and 1. To perform calculations with them, one needs to execute quantum logic operations, also known as quantum gates.
Electron–atom scattering encodes the quantum state of electron wave packets
A new analysis reveals what happens when very short or narrow electron beams encounter a particle. The research is published in the New Journal of Physics. Scientists should be able to achieve a new level of control over high-energy electrons interacting with a particle, according to the theoretical analysis by a RIKEN physicist and two colleagues.
Electrons are particles, but according to quantum mechanics they also behave like waves under certain circumstances.
Electron microscopes exploit this wave-like nature of electrons to obtain high-resolution images of objects by imaging how an electron beam is scattered from an object.
Giant Atoms for Measuring Radiation
The invention of the radio just over a century ago transformed people’s ability to communicate. Suddenly, people could send and receive light-speed messages from thousands of miles away — a capability that continues to transform the world.
Soon, quantum scientists could usher in the next big advance in radio communication: compact, highly sensitive receivers based on atoms.
Atoms are typically far too small to interact with radio waves. But one of quantum theory’s stranger predictions is the possibility of gargantuan atoms with diameters up to the width of a human hair.
How a century-long argument over light’s true nature came to an end
Two of the forefathers of quantum theory, Albert Einstein and Niels Bohr, had a famous argument over whether light is a wave or a particle. Columnist Karmela Padavic-Callaghan finds that the matter has been settled once and for all.