Laser Beyond the Standard Quantum Limit

  • By Samantha Whelpley
  • 5 February 2021

Research led by David Pekker was recently featured in an article on Gizmodo titled “Physicists are Reinventing the Laser”. The work was from Pekker’s paper titled “A New Quantum Limit on Laser Linewidth,” co-authored with Michael Hatridge, Chenxu Liu, Maria Mucci, Xi Cao, and Gurudev Dutt.

Their research finds that the Schawlow-Townes limit, an equation used to find the coherence time limit for lasers, is no longer an accurate estimate and that it can be possible to build more coherent lasers. Pekker and his coworkers found that by placing a valve on a laser to control the flow of protons, the laser’s coherence time can be extended beyond the Schawlow-Townes limit.

This is important because of its modern applications to quantum computing. Pekker and Hatridge plan to build this new laser design, which involves a microwave-emitting laser (or maser) to use for programming qubits inside a quantum computer made of superconducting circuits.