Princeton University researchers have built a rice grain-sized laser powered by single electrons tunneling through artificial atoms known as quantum dots. The tiny microwave laser, or “maser,” is a demonstration of the fundamental interactions between light and moving electrons. (more…)
Forscher der University of Waterloo und der Universität Innsbruck haben erstmals drei miteinander verschränkte Photonen unabhängig von einander gemessen. Die in der Zeitschrift Nature Photonics veröffentlichten Ergebnisse bestätigen eindrucksvoll die Theorie der Quantenverschränkung.
Quantenphysik zeichnet sich durch einige für den Laien schwer verständliche Eigenschaften aus. So geht die klassische Physik davon aus, dass Vorgänge nur Auswirkungen auf ihre direkte räumliche Umgebung haben. Die in der Quantenmechanik formulierte Möglichkeit, dass verschränkte Teilchen auch über weite Distanzen hinweg stark miteinander verbunden sein können, veranlasste Albert Einstein einmal dazu, von einer „spukhaften Fernwirkung“ zu sprechen. Bis heute suchen deshalb Zweifler nach möglichen verborgenen Eigenschaften, die die Quantenmechanik doch den Gesetzen der klassischen Physik unterordnen. Diese Bemühungen erfahren nun erneut einen Rückschlag. Mit der örtlich unabhängigen Messung von drei miteinander verschränkten Photonen bestätigen Physiker um Gregor Weihs vom Institut für Experimentalphysik der Universität Innsbruck sowie Thomas Jenewein und Kevin Resch vom Institute for Quantum Computing (IQC) der University of Waterloo in Kanada eindrucksvoll die Richtigkeit der Quantenmechanik. (more…)
Collaboration at Berkeley Lab’s Advanced Light Source Induces High Temperature Superconductivity in a Toplogical Insulator
Reliable quantum computing would make it possible to solve certain types of extremely complex technological problems millions of times faster than today’s most powerful supercomputers. Other types of problems that quantum computing could tackle would not even be feasible with today’s fastest machines. The key word is “reliable.” If the enormous potential of quantum computing is to be fully realized, scientists must learn to create “fault-tolerant” quantum computers. A small but important step toward this goal has been achieved by an international collaboration of researchers from China’s Tsinghua University and the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) working at the Advanced Light Source (ALS). (more…)
Using ultra-fast laser pulses, a team of researchers led by UA assistant professor Vanessa Huxter has made the first detailed observation of how energy travels through diamonds containing nitrogen-vacancy centers – promising candidates for a variety of technological advances such as quantum computing.
A team of researchers led by University of Arizona assistant professor Vanessa Huxter has made the first detailed observation of how energy travels through diamonds that contain nitrogen-vacancy centers – defects in which two adjacent carbon atoms in the diamond’s crystal structure are replaced by a single nitrogen atom and an empty gap. (more…)
The next generation of computers promises far greater power and faster processing speeds than today’s silicon-based based machines. These “quantum computers” — so called because they would harness the unique quantum mechanical properties of atomic particles — could draw their computing power from a collection of super-cooled molecules.
But chilling molecules to a fraction of a degree above absolute zero, the temperature at which they can be manipulated to store and transmit data, has proven to be a difficult challenge for scientists. (more…)
Berkeley Lab scientists discover how a photon beam can flip the spin polarization of electrons emitted from an exciting new material
Plain-looking but inherently strange crystalline materials called 3D topological insulators (TIs) are all the rage in materials science. Even at room temperature, a single chunk of TI is a good insulator in the bulk, yet behaves like a metal on its surface.
Researchers find TIs exciting partly because the electrons that flow swiftly across their surfaces are “spin polarized”: the electron’s spin is locked to its momentum, perpendicular to the direction of travel. These interesting electronic states promise many uses – some exotic, like observing never-before-seen fundamental particles, but many practical, including building more versatile and efficient high-tech gadgets, or, further into the future, platforms for quantum computing. (more…)
Yale University scientists have found a way to observe quantum information while preserving its integrity, an achievement that offers researchers greater control in the volatile realm of quantum mechanics and greatly improves the prospects of quantum computing.
Quantum computers would be exponentially faster than the most powerful computers of today. (more…)
Three University of Chicago chemistry professors hope that their separate research trajectories will converge to create a new way of assembling what they call “designer atoms” into materials with a broad array of potentially useful properties and functions.
These “designer atoms” would be nanocrystals—crystalline arrays of atoms intended to be manipulated in ways that go beyond standard uses of atoms in the periodic table. Such arrays would be suited to address challenges in solar energy, quantum computing and functional materials. (more…)
