Lifeboat Foundation

While atomic clocks are already the most precise timekeeping devices in the universe, physicists are working hard to improve their accuracy even further. One way is by leveraging spin-squeezed states in clock atoms.

Spin-squeezed states are entangled states in which particles in the system conspire to cancel their intrinsic quantum noise. These states, therefore, offer great opportunities for quantum-enhanced metrology since they allow for more precise measurements. Yet, spin-squeezed states in the desired optical transitions with little outside noise have been hard to prepare and maintain.

One particular way to generate a spin-squeezed state, or squeezing, is by placing the clock atoms into an optical cavity, a set of mirrors where light can bounce back and forth many times. In the cavity, atoms can synchronize their photon emissions and emit a burst of light far brighter than from any one atom alone, a phenomenon referred to as superradiance. Depending on how superradiance is used, it can lead to entanglement, or alternatively, it can instead disrupt the desired quantum state.

A team of physicists, including University of Massachusetts assistant professor Tigran Sedrakyan, recently announced in the journal Nature that they have discovered a new phase of matter. Called the “chiral Bose-liquid state,” the discovery opens a new path in the age-old effort to understand the nature of the physical world.

Under everyday conditions, matter can be a solid, liquid or gas. But once you venture beyond the everyday—into temperatures approaching absolute zero, things smaller than a fraction of an atom or which have extremely low states of energy—the world looks very different. “You find quantum states of matter way out on these fringes,” says Sedrakyan, “and they are much wilder than the three classical states we encounter in our everyday lives.”

Sedrakyan has spent years exploring these wild quantum states, and he is particularly interested in the possibility of what physicists call “band degeneracy,” “moat bands” or “kinetic frustration” in strongly interacting quantum matter.

The quantum ground state of an acoustic wave of a certain frequency can be reached by completely cooling the system. In this way, the number of quantum particles, the so-called acoustic phonons, which cause disturbance to quantum measurements, can be reduced to almost zero and the gap between classical and quantum mechanics bridged.

Over the past decade, major technological advances have been made, making it possible to put a wide variety of systems into this state. Mechanical vibrations oscillating between two mirrors in a resonator can be cooled to very low temperatures as far as the quantum ground state. This has not yet been possible for optical fibers in which high-frequency sound waves can propagate. Now researchers from the Stiller Research Group have taken a step closer to this goal.

According to a recent study from the University of Helsinki, published in the journal Physical Review Letters, a vortex of a superfluid that has been quantized four times has three ways of dividing, depending on the temperature.

The fluid transforms into a superfluid near the absolute zero point of temperature (approximately −273°C). Internal resisting forces, such as friction, disappear. At this point, the behavior of the fluid can no longer be described using classical mechanics; instead, quantum physics must be applied.

When a superfluid is spun, the resulting rotation should never slow down because superfluids have no viscosity or friction. This has been experimented with at the atomic level using helium at very slow rotation, and it was observed that the superfluid, however, eventually halted.

A collaborative project has made a breakthrough in enhancing the speed and resolution of widefield quantum sensing, leading to new opportunities in scientific research and practical applications.

By collaborating with scientists from Mainland China and Germany, the team has successfully developed a quantum sensing technology using a neuromorphic vision sensor, which is designed to mimic the human vision system. This sensor is capable of encoding changes in fluorescence intensity into spikes during optically detected magnetic resonance (ODMR) measurements.

The key advantage of this approach is that it results in highly compressed data volumes and reduced latency, making the system more efficient than traditional methods. This breakthrough in quantum sensing holds potential for various applications in fields such as monitoring dynamic processes in biological systems.

Quantum computing engineers at UNSW Sydney have shown they can encode quantum information—the special data in a quantum computer—in four unique ways within a single atom, inside a silicon chip.

The feat could alleviate some of the challenges in operating tens of millions of quantum computing units in just a few square millimeters of a silicon quantum computer chip.

In a paper published in Nature Communications, the engineers describe how they used the 16 quantum ‘states’ of an antimony atom to encode quantum information.

A team of researchers has won funding from the US Air Force Office of Scientific Research to address the challenges posed by silicon spin qubits.

The industry is discovering new ways to standardize the production of the novel machines.

Last year, a Quantinuum-led team of scientists announced that they were able to realize and control a state of matter known as non-Abelian topological order within a quantum processor. The team published their results in the pre-print server ArXiv, outlining how they accomplished what many experts considered a far-off advance — if possible at all – and what the scientists hoped could be an advance toward revolutionizing the way we approach quantum computing.

That advance has now been officially peer reviewed in Nature, marking another important step in the scientific process – and maybe even a significant step in the quest for fault-tolerant quantum computers, a quantum device that could handle operations with unprecedented accuracy and efficiency.

“Our key finding is that non-Abelian topological orders can experimentally be prepared with high fidelities on par with Abelian states like the surface code,” the team writes. “Non-Abelian states are among the most intricately entangled quantum states theoretically known to exist, and carry promise for new types of quantum information processing. Their realization evidences the rapid development of quantum devices and opens several new questions.”