Lifeboat Foundation

Monolayer 2D semiconductors, such as WS2, exhibit uniquely strong light–matter interactions due to exciton resonances that enable atomically thin optical elements. Similar to geometry-dependent plasmon and Mie resonances, these intrinsic material resonances offer coherent and tunable light scattering. Thus far, the impact of the excitons’ temporal dynamics on the performance of such excitonic metasurfaces remains unexplored. Here, we show how the excitonic decay rates dictate the focusing efficiency of an atomically thin lens carved directly out of exfoliated monolayer WS2. By isolating the coherent exciton radiation from the incoherent background in the focus of the lens, we obtain a direct measure of the role of exciton radiation in wavefront shaping. Furthermore, we investigate the influence of exciton–phonon scattering by characterizing the focusing efficiency as a function of temperature, demonstrating an increased optical efficiency at cryogenic temperatures. Our results provide valuable insights into the role of excitonic light scattering in 2D nanophotonic devices.

I’m sure some of you have looked at robo mowers as Roombas for your yard but, sadly, many of them require you to install a boundary wire around the perimeter of your lawn. And any product that requires you to dig a trench is the opposite of what “low effort” means to me. That’s why I was interested in trying Segway’s Navimow i105, its £945 (around $1,200) GPS-equipped mower which eliminates that busywork. And keeping your lawn neat and tidy is a job that’s all busywork.

Ask a gardener and they’ll tell you the secret to a great lawn is to seed a piece of flat land and then mow it into submission. Regular, militant mowing kills off all the other flora, ensuring only grass can grow until everything looks well-manicured. But that relentless mowing requires a lot of time, a luxury I’ve never had. It’s the sort of job a robot mower was born to do, given it can scuttle around and trim grass without you there.

Segway’s i Series is the company’s latest, more affordable offering compared to its pricier S Series. The new units have a smaller battery and range, with the i105 able to handle areas up to 500 square meters. Unlike some GPS mowers, the i105 is equipped with a forward facing HD camera with a 180-degree field of vision. So while it relies on satellites for positioning, it’ll have enough sense to stop before it clatters into an obstacle. It’s not packing sophisticated computer vision smarts, but it’ll play safe lest it charge into a pet, inattentive family member or prized flower.

Have you ever wondered what happens when thousands of particles of light merge into a single entity? This phenomenon, known as a “super photon,” has fascinated physicists for years.

Now, researchers have made an intriguing discovery that broadens our understanding of this exotic quantum state.

Dr. Julian Schmitt and his colleagues from the Institute of Applied Physics at the University of Bonn have shown that photon Bose-Einstein condensates, also known as quantum gases, obey a fundamental theorem of physics.

The billionaire’s bank balance won’t necessarily be $56 billion bigger if the vote really does go his way, since it’s non-binding. Expect the saga to continue.

Is it real? Well, it’s a real “arc” reactor that generates plasma, but as we explained in the beginning of the video, it’s impossible to create a device that…

“Every simply connected, closed 3-manifold is homeomorphic to the 3-sphere.” — The Poincaré Conjecture.

“Every simply connected, closed 3-manifold is homeomorphic to the 3-sphere.”

- The Poincaré Conjecture photo credit : https://bit.ly/2KDYLoC

Continue reading “Graphics Archive — Special Topics: Hyperbolic Geometry” »

The Air Force top officer eluded confirmation that it would still field NGAD given the current and future budget restrictions plaguing the Defense Department.

Join our newsletter to get the latest military space news every Tuesday by veteran defense journalist Sandra Erwin.

The three companies will compete for orders over the contract period starting in fiscal year 2025 through 2029. Under the NSSL program, the Space Force orders individual launch missions up to two years in advance. At least 30 NSSL Lane 1 missions are expected to be competed over the five years.

Observing gravitational-wave memory may help physicists test general relativity predictions about large-scale symmetries in the fabric of spacetime.