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Entanglement in hybrid quantum systems comprised of fundamentally different degrees of freedom, such as light and mechanics, is of interest for a wide range of applications in quantum technologies. Here, we propose to engineer bipartite entanglement between traveling acoustic phonons in a Brillouin active solid state system and the accompanying light wave. The effect is achieved by applying optical pump pulses to state-of-the-art waveguides, exciting a Brillouin Stokes process. This pulsed approach, in a system operating in a regime orthogonal to standard optomechanical setups, allows for the generation of entangled photon-phonon pairs, resilient to thermal fluctuations. We propose an experimental platform where readout of the optoacoustics entanglement is done by the simultaneous detection of Stokes and anti-Stokes photons in a two-pump configuration.

A new quantum entanglement approach by Max-Planck-Institute scientists uses Brillouin scattering to link photons with acoustic phonons, enhancing stability and operating at higher temperatures.

Quantum entanglement is essential for many cutting-edge quantum technologies, including secure quantum communication and quantum computing. Researchers at the Max Planck Institute for the Science of Light (MPL) have developed an efficient new method to entangle photons with acoustic phonons. Their approach overcomes one of the most significant challenges in quantum technology—vulnerability to external noise. This groundbreaking research, published on November 13 in Physical Review Letters, opens new possibilities for robust quantum systems.

Exploring Optoacoustic Entanglement

This behavior is driven by quantum entanglement, a phenomenon where the fates of individual electrons become intertwined.

Scientists have developed theoretical models describing quantum spin liquids for many years. However, creating these materials in a laboratory setting has been a challenge.

This is because, in most materials, electron spins tend to settle into an ordered state, similar to the alignment seen in conventional magnets.

Scientists have pioneered a new material based on ruthenium that demonstrates complex, disordered magnetic properties akin to those predicted for quantum spin liquids, an elusive state of matter.

This breakthrough in the study indicates significant potential for the development of quantum materials that transcend classical physical laws, providing new insights and applications in the quantum realm.

Novel Quantum Materials

The multiverse offers no escape from our reality—which might be a very good thing.

By George Musser

As memes go, it wasn’t particularly viral. But for a couple of hours on the morning of November 6, the term “darkest timeline” trended in Google searches, and several physicists posted musings on social media about whether we were actually in it. All the probabilities expressed in opinion polls and prediction markets had collapsed into a single definite outcome, and history went from “what might be” to “that just happened.” The two sides in this hyperpolarized U.S. presidential election had agreed on practically nothing—save for their shared belief that its outcome would be a fateful choice between two diverging trajectories for our world.

What if our universe is not the only one? What if it is just a tiny bubble inside a much larger and more complex reality? This is the idea behind the bubble universe theory, which suggests that our universe is one of many possible universes that exist inside a black hole.

What is a bubble universe?

A bubble universe is a hypothetical region of space that has different physical laws and constants than the rest of the multiverse. The multiverse is the collection of all possible universes that exist or could exist. A bubble universe could form when a quantum fluctuation creates a tiny pocket of space with different properties than its surroundings. This pocket could then expand and inflate into a large and isolated universe, like a bubble in a glass of water.