Two teams of researchers have published papers [1, 2] in the journal Nature detailing how they were able to create unprecedented quantum simulators consisting of over 50 qubits. The University of Maryland team and National Institute of Standards and Technology team — the two teams behind one of the two new papers — were able to create a quantum simulator with 53 qubits. Motherboard reports: Quantum simulators are a special type of quantum computer that uses qubits to simulate complex interactions between particles. Qubits are the informational medium of quantum computers, analogous to a bit in an ordinary computer. Yet rather than existing as a 1 or 0, as is the case in a conventional bit, a qubit can exist in some superposition of both of these states at the same time. For the Maryland experiment, each of the qubits was a laser cooled ytterbium ion. Each ion had the same electrical charge, so they repelled one another when placed in close proximity. The system created by Monroe and his colleagues used an electric field to force the repelled ions into neat rows. At this point, lasers are used to manipulate all the ytterbium qubits into the same initial state. Then another set of lasers is used to manipulate the qubits so that they act like atomic magnets, where each ion has a north and south pole. The qubits either orient themselves with their neighboring ions to form a ferromagnet, where their magnetic fields are aligned, or at random. By changing the strength of the laser beams that are manipulating the qubits, the researchers are able to program them to a desired state (in terms of magnetic alignment). According to Zhexuan Gong, a physicist at the University of Maryland, the 53 qubits can be used to simulate over a quadrillion different magnetic configurations of the qubits, a number that doubles with each additional qubit added to the array. As these types of quantum simulators keep adding more qubits into the mix, they will be able to simulate ever more complex atomic interactions that are far beyond the capabilities of conventional supercomputers and usher in a new era of physics research. Another team from Harvard and Maryland also released a paper today in which it demonstrated a quantum simulator using 51 qubits. Read more of this story at Slashdot.
See more here:
Physicists Made An Unprecedented 53 Qubit Quantum Simulator
An anonymous reader quotes a report from The Guardian: The blaring, grinding noise jolted the American diplomat from his bed in a Havana hotel. He moved just a few feet, and there was silence. He climbed back into bed. Inexplicably, the agonizing sound hit him again. It was as if he’d walked through some invisible wall cutting straight through his room. Soon came the hearing loss, and the speech problems, symptoms both similar and altogether different from others among at least 21 U.S. victims in an astonishing international mystery still unfolding in Cuba. The top U.S. diplomat has called them “health attacks.” New details learned by the Associated Press indicate at least some of the incidents were confined to specific rooms or even parts of rooms with laser-like specificity, baffling U.S. officials who say the facts and the physics don’t add up. Suspicion initially focused on a sonic weapon, and on the Cubans. Yet the diagnosis of mild brain injury, considered unlikely to result from sound, has confounded the FBI, the state department and U.S. intelligence agencies involved in the investigation. Some victims now have problems concentrating or recalling specific words, several officials said, the latest signs of more serious damage than the U.S. government initially realized. The United States first acknowledged the attacks in August — nine months after symptoms were first reported. Read more of this story at Slashdot.