Fibonacci pulses extend coherence
Researchers used Fibonacci-sequenced laser pulses in a 10‑atom quantum simulator to create a 'two-time' quasicrystal phase that preserved quantum states for about 5.5 seconds — roughly four times longer than previously observed. (x.com) The result was reported alongside a Nature paper and flagged in coverage as a quantum-control advance in small simulators. (x.com)
Quantum computers store information in qubits, but qubits lose their state when stray noise, control errors or cross-talk build up over time. In a July 20, 2022 Nature paper, researchers reported a way to keep that information intact longer by driving a 10-atom trapped-ion simulator with a quasiperiodic pulse pattern based on the Fibonacci sequence. (nature.com) The team used 10 ytterbium ion qubits in Quantinuum’s System Model H1 processor in Broomfield, Colorado. Philipp Dumitrescu, Brian Neyenhuis, Romain Vasseur and Andrew Potter were among the authors on the experiment and theory. (nature.com) Instead of hitting the qubits with a perfectly repeating beat, the researchers used a quasiperiodic drive, a pattern that never exactly repeats but still follows a fixed rule. Their rule came from the Fibonacci sequence, and the resulting state behaved as if it had an extra direction in time, according to the paper and a Simons Foundation report published the same day. (nature.com) (simonsfoundation.org) That matters because repeating drives can create useful quantum phases, but those phases often fall apart when real hardware adds small imperfections. The Nature paper said the quasiperiodic version protected the edge qubits from control errors, stray fields and cross-talk in a way the periodic version did not. (nature.com) The protected qubits sat at the ends of the 10-ion chain, where topological protection can make boundary states harder to disturb. In plain terms, the experiment used the system’s overall pattern, not just fine-tuned settings, to shelter information stored on those edge qubits. (nature.com) (simonsfoundation.org) The paper placed the result in the broader search for non-equilibrium phases, states that appear only when a quantum system is being actively driven rather than left at rest. Earlier work had already shown time crystals and other driven phases in trapped ions, solid-state spins, ultracold atoms and superconducting qubits. (nature.com 1) (nature.com 2) The 2022 result was also a small-system demonstration, not a full error-corrected quantum computer. The authors said it showed a route toward more complex dynamical topological orders that could eventually support more error-resilient quantum information processing. (nature.com) So the core idea is simple even if the physics is not: by replacing a regular laser rhythm with a Fibonacci-style one, the researchers made a fragile 10-qubit system hold on to quantum information longer. The experiment turned timing itself into part of the protection scheme. (nature.com) (eurekalert.org)
