Artist’s view of individual electrons interacting with an optical whispering gallery mode as it circles a silica sphere. The matching between the velocities of the electron and the light-wave it is riding changes the quantum state of the electron, illustrated as a wider halo. Credit: Dr. Murat Sivis.
The famous cat-in-a-box thought experiment by Austrian physicist Erwin Schrödinger is an illustration of one of the defining characteristics of quantum mechanics — the unpredictable behaviour of particles at the quantum level.
It makes working with quantum systems incredibly difficult; but what if we could make quantum predictions? A team of physicists believes it’s possible.
In a study published last year, they demonstrated their ability to predict something called a quantum jump, and even reverse the process after it’s started.
Physicists set a new record by linking together a hot soup of 15 trillion atoms in a bizarre phenomenon called quantum entanglement. The finding could be a major breakthrough for creating more accurate sensors to detect ripples in space-time called gravitational waves or even the elusive dark matter thought to pervade the universe.
Entanglement, a quantum phenomena Albert Einstein famously described as “spooky action at a distance,” is a process in which two or more particles become linked and any action performed on one instantaneously affects the others regardless of how far apart they are. Entanglement lies at the heart of many emerging technologies, such as quantum computing and cryptography.
Scientists create smallest semiconductor laser that works in visible range at room temperature.
An international team of researchers led by researchers from ITMO University announced the development of the world’s most compact semiconductor laser that works in the visible range at room temperature. According to the authors of the research, the laser is a nanoparticle of only 310 nanometers in size (which is 3,000 times less than a millimeter) that can produce green coherent light at room temperature. The research article was published in ACS Nano.
This year, the international community of optical physicists celebrates the anniversary of a milestone event: 60 years ago, in the middle of May, American physicist Theodor Maiman demonstrated the operation of the first optical quantum generator — a laser. Now, Sixty years later, an international team of scientists published a work where they demonstrated experimentally the world’s most compact semiconductor laser that operates in the visible range at room temperature. This means that the coherent green light that it produces can be easily registered and even seen by a naked eye using a standard optical microscope.
Physicists have measured the flight times of electrons emitted from a specific atom in a molecule upon excitation with laser light. This has enabled them to measure the influence of the molecule itself on the kinetics of emission.
Photoemission — the release of electrons in response to excitation by light — is one of the most fundamental processes in the microcosm. The kinetic energy of the emitted electron is characteristic for the atom concerned, and depends on the wavelength of the light employed. But how long does the process take? And does it always take the same amount of time, irrespective of whether the electron is emitted from an individual atom or from an atom that is part of a molecule? An international team of researchers led by laser physicists in the Laboratory for Attosecond Physics (LAP) at LMU Munich and the Max Planck Institute of Quantum Optics (MPQ) in Garching has now probed the influence of the molecule on photoemission time.
The theoretical description of photoemission in 1905 by Albert Einstein marked a breakthrough in quantum physics, and the details of the process are of continuing interest in the world of science and beyond. How the motions of an elementary quantum particle such as the electron are affected within a molecular environment has a significant bearing on our understanding of the process of photoemission and the forces that hold molecules together.
While tech-industry heavyweights strive for quantum supremacy, IDC’s latest research reveals the current state of quantum computing and explains why real-world applications are only a qubit away.
The theory of relativity describes black holes as being spherical, smooth and simple. Quantum theory describes them as being extremely complex and full of information. New research now proposes a surprising solution to this apparent duality.
Researchers from the Moscow Institute of Physics and Technology, joined by a colleague from Argonne National Laboratory, U.S., have implemented an advanced quantum algorithm for measuring physical quantities using simple optical tools. Published in Scientific Reports, their study takes us a step closer to affordable linear optics-based sensors with high performance characteristics. Such tools are sought after in diverse research fields, from astronomy to biology.
Maximizing the sensitivity of measurement tools is crucial for any field of science and technology. Astronomers seek to detect remote cosmic phenomena, biologists need to discern exceedingly tiny organic structures, and engineers have to measure the positions and velocities of objects, to name a few examples.
Until recently, no measurement tool could ensure precision above the so-called shot noise limit, which has to do with the statistical features inherent in classical observations. Quantum technology has provided a way around this, boosting precision to the fundamental Heisenberg limit, stemming from the basic principles of quantum mechanics. The LIGO experiment, which detected gravitational waves for the first time in 2016, shows it is possible to achieve Heisenberg-limited sensitivity by combining complex optical interference schemes and quantum techniques.
In the consumer electronics industry, quantum dots are used to dramatically improve color reproduction in TV displays. That’s because LCD TV displays, the kind in most of our living rooms, require a backlight. This light is typically made up of white, or white-ish LEDs. The LCD filters the white light into red, green, and blue pixels; their combinations create the colors that appear on the screen.
Before quantum dots, filtering meant that much of the light didn’t make it to the screen. Putting a layer of quantum dots between the LEDs and the LCD, however, changes that equation. QD TVs use blue LEDs as the light source, then take advantage of the quantum effect to shift some of that light to tightly constrained red and green wavelengths. Because only this purified light reaches the filters—instead of the full spectrum that makes up white light—far less is blocked and wasted.
It turns out that this same approach to making your TV picture better can make plants grow faster, because plants, like LCD filters, are tuned to certain colors of light.
