Lifeboat Foundation

As part of Conversations on the Quantum World, a webinar series hosted by the Caltech Science Exchange, Professor of Theoretical Physics Kathryn Zurek and Professor of Physics Rana Adhikari talk about one of the biggest mysteries in physics today: quantum gravity.

Quantum gravity refers to a set of theories attempting to unify the microscopic world of quantum physics with the macroscopic world of gravity and space itself. Zurek, a theorist, and Adhikari, an experimentalist, have teamed up with others to design a new tabletop-size experiment with the potential to detect signatures of quantum gravity.

Continue reading “Ask a Caltech Expert: Physicists Explain Quantum Gravity” »

https://doi.org/10.1101/2022.12.21.

Community Detection in Brain Connectome using Quantum Annealer Devices:

Continue reading “Community Detection in Brain Connectome using Quantum Annealer Devices #quantum #brain #networks” »

A wild theory suggests that consciousness may explain quantum mechanics, by forcing the subatomic particles to choose one concrete outcome.

There could be variables beyond the ones we’ve identified and know how to measure. But they can’t get rid of quantum weirdness.

Optomechanics simulates graphene lattices.

Experts are warning that quantum computers could eventually overpower conventional encryption methods, a potentially dangerous fate for humanity that they’re evocatively dubbing the “quantum apocalypse,” the BBC reports.

Cracking today’s toughest encryption would take virtually forever today — but with the advent of quantum computers, they’re warning, the process could be cut down to mere seconds.

And that kind of number-crunching power could have disastrous consequences if it were to land in the wrong hands.

Lasers have been used to throw and catch extremely cold, single atoms. The technique could be used to assemble quantum computers in the future.

Ordinarily, to measure an object we must interact with it in some way. Whether it’s by a prod or a poke, an echo of sound waves, or a shower of light, it’s near impossible to look without touching.

In the world of quantum physics, there are some exceptions to this rule.

Researchers from Aalto University in Finland propose a way to ‘see’ a microwave pulse without the absorption and re-emission of any light waves. It’s an example of a special interaction-free measurement, where something is observed without being rattled by a mediating particle.

This year’s Nobel Prize in Physics celebrated the fundamental interest of quantum entanglement, and also envisioned the potential applications in “the second quantum revolution”—a new age when we are able to manipulate the weirdness of quantum mechanics, including quantum superposition and entanglement. A large-scale and fully functional quantum network is the holy grail of quantum information sciences. It will open a new frontier of physics, with new possibilities for quantum computation, communication, and metrology.

One of the most significant challenges is to extend the distance of quantum communication to a practically useful scale. Unlike classical signals that can be noiselessly amplified, quantum states in superposition cannot be amplified because they cannot be perfectly cloned. Therefore, a high-performance quantum network requires not only ultra-low-loss quantum channels and quantum memory, but also high-performance quantum light sources. There has been exciting recent progress in satellite-based quantum communications and quantum repeaters, but a lack of suitable single-photon sources has hampered further advances.

What is required of a single-photon source for quantum network applications? First, it should emit one (only one) photon at a time. Second, to attain brightness, the single-photon sources should have high system efficiency and a high repetition rate. Third, for applications such as in quantum teleportation that require interfering with independent photons, the single photons should be indistinguishable. Additional requirements include a scalable platform, tunable and narrowband linewidth (favorable for temporal synchronization), and interconnectivity with matter qubits.