NIST physicists have successfully entangled six beryllium ions, creating a quantum “cat” state where the ions exist in two opposite spin states simultaneously. This achievement, published in Nature, represents a significant step forward in quantum physics research and has potential applications in quantum computing, cryptography, and ultra-sensitive measurements.
The experiment involved placing six ions in a superposition of spin states, where each ion could be measured as either spin up or spin down with equal probability. The ions were then entangled using a NIST-developed technique that couples their spin states to their collective motion. This created a cat state, where the ions’ spins were in a superposition of all spins up and all spins down simultaneously.
The ability to create and maintain such complex quantum states is crucial for developing advanced quantum technologies. Cat states, with their sensitivity to disturbances, could be useful in fault-tolerant quantum computing and quantum encryption. Additionally, the entangled ions could improve precision instruments like atomic clocks and magnetic field sensors.
The experiment, while a long way from entangling a macroscopic object like a cat, extends the domain where Schrödinger cat states can exist to at least six atoms. This research builds on previous work with fewer entangled particles and represents a significant advancement in the field of quantum physics.
Source: https://www.nist.gov/news-events/news/2005/11/nist-physicists-coax-six-atoms-quantum-cat-state
Keywords: spin, superposition, entanglement, quantum, computers, ions
