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, but the same method hasn’t worked as well in building tiny lasers that emit green light. Green laser pointers have existed for 25 years but only produce light in a narrow spectrum of green and are not integrated in chips. Researchers refer to the dearth of stable, miniature lasers in this region of the visible-light spectrum as the “green gap.” Now a team led by JQI Fellow Kartik Srinivasan has closed the green gap by modifying a tiny optical component: a ring-shaped microresonator, small enough to fit on a chip.
Entangling four logical qubits beyond break-even in a nonlocal code
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.