Tiny New Lasers Fill a Long-Standing Gap in Visible-Light Colors, Opening New Applications

It’s not easy making green.

For years, scientists have fabricated small, high-quality lasers that generate red and blue light. However, the method they typically employ—injecting electric current into semiconductors—hasn’t worked as well in building tiny lasers that emit light at yellow and green wavelengths. Researchers refer to the dearth of stable, miniature lasers in this region of the visible-light spectrum as the “green gap.” Filling this gap opens new opportunities in underwater communications, medical treatments and more.

Entangling four logical qubits beyond break-even in a nonlocal code

Abstract: Quantum error correction protects logical quantum information against environmental decoherence by encoding logical qubits into entangled states of physical qubits. One of the most important near-term challenges in building a scalable quantum computer is to reach the break-even point, where logical quantum circuits on error-corrected qubits achieve higher fidelity than equivalent circuits on uncorrected physical qubits.