Lifeboat Foundation: Safeguarding Humanity
Toggle light / dark theme

Blog

Category: quantum physics – Page 12

Quantum gas resists heating under periodic kicks, revealing many-body localization mechanism

A joint theoretical study by the University of Innsbruck and Zhejiang University has uncovered the microscopic origin of a striking quantum phenomenon: a periodically driven gas of ultracold atoms that simply refuses to heat up, defying classical expectations.

Push a swing repeatedly in rhythm, and it swings higher and higher, absorbing more and more energy. A quantum gas, however, can behave very differently. Under periodic kicks, quantum interference can freeze energy absorption entirely, a phenomenon known as dynamical localization. Whether this survives when particles interact with each other has been a long-standing open question. A 2025 experiment by the research group of Hanns-Christoph Nägerl at the Department of Experimental Physics confirmed that it can. But the microscopic reasons remained until now unclear.

A new theoretical study by Prof. Lei Ying’s team at Zhejiang University, in collaboration with Prof. Hanns-Christoph Nägerl’s group at the University of Innsbruck, published in Physical Review Letters, provides the missing explanation. The team developed a mathematical framework that transforms the complex-driven many-body problem into a tractable lattice model. This reveals that interactions introduce a universal power-law structure that reshapes localization—and ultimately drives its breakdown at intermediate interaction strengths.

Two paths to scalable quantum computing: Optical links between fridges and higher-temperature qubits

Superconducting qubits—bits of quantum information—have been widely considered a promising technology for moving quantum computing forward. But there’s still much work to be done before they can be brought out of a near absolute zero temperature environment. The lab of Professor Hong Tang has recently published two studies that advance the technology.

To solve practical problems, quantum processors need a lot of qubits—up to thousands to millions. Such a large number of qubits requires significantly complex wiring and a way to store them at a temperature colder than deep space. This is complicated by the physical size of the cryogenic devices, known as dilution refrigerators, that maintain qubits at a temperature just above absolute zero. In a study published in Nature Photonics, Tang’s research team has found a way around this obstacle.

A flexible and cost-effective solution is to build a quantum network by connecting qubits inside separate refrigerators. Connecting qubits with standard coaxial cables, however, wouldn’t work if those cables were kept in a room temperature environment. And storing them all in one very cold room would be near impossible. Even under an optimistic assumption of 1,000 qubits per refrigerator, scaling to 1 million qubits would require linking 1,000 refrigerators—an arrangement that is physically impractical within a single room.

Could the mathematical ‘shape’ of the universe solve the cosmological constant problem?

The cosmological constant is the mathematical description of the energy that drives the ever-accelerating expansion of the cosmos. It’s also the source of one of the most enduring and confounding problems in modern physics.

The constant’s observed value is fundamentally at odds with quantum field theory (QFT), the leading theory describing the elementary particles and forces that make up the universe. QFT predicts that quantum fluctuations in the vacuum of space should make the value of the constant enormous—practically infinite. But its observed value is a tiny fraction of that prediction.

Researchers at Brown University have proposed a provocative new answer for why that is.

Why ultrashort laser pulses could make low-power electron sources far more practical

A new theoretical study finds shorter laser pulses achieve higher quantum efficiency for photoemission from a solid surface without increasing power or intensity. Using light to knock electrons loose from a surface—known as photoemission—may soon be achievable more easily in smaller labs with smaller lasers. Shortening the length of a laser pulse can increase the emitted electrons by several orders of magnitude without increasing the laser intensity or power, according to a University of Michigan Engineering study.

The study is published in Physical Review Research.

Efficient, low-power photoemission could make particle acceleration and high-resolution imaging techniques to visualize cells and atoms more accessible. It could also help researchers develop lightwave electronics, which use light to move charge carriers, for ultrafast computing.

Water simulation of famous quantum effect reveals unexpected wave patterns

In the quirky quantum world, particles can be affected by forces that they never directly encounter. A classic example is the Aharonov–Bohm (AB) effect, where electrons are affected by a magnetic field, despite not passing through it. Although predicted in 1959, it took more than two decades to confirm this effect experimentally, as the specific changes to the electrons’ wave properties could only be inferred indirectly, and with great difficulty. Now, physicists from the Okinawa Institute of Science and Technology (OIST), in collaboration with the University of Oslo and Universidad Adolfo Ibáñez, have used a classical fluid analog that mimics and extends the AB effect using a simple platform: a water tank.

In work published in Communications Physics, researchers have revealed that when water waves are sent towards a swirling vortex from opposite directions, it causes a striking pattern, with one or more lines of momentarily still water radiating outward and rotating in an almost hypnotic way.

“This was something new and unexpected,” says Aditya Singh, a Ph.D. student in the Nonlinear and Non-equilibrium Physics Unit and co-first author of the study. “That’s what makes this fluid analog system so valuable. It reveals topological effects—wave behaviors that occur across the whole system—that can’t be seen in quantum experiments.”

Atomic Clocks Could Reveal The Hidden Quantum Nature of Time Itself

Although there are many variables in life, there’s one metric by which our existence is strictly measured: time.

We think of it as rigid, smooth, and unidirectional – the arrow of time flies straight and true, and all we can do is go where it leads.

But what if time is a little more loosey-goosey than our experience of it suggests? What if it harbors a hidden quantum nature?

Feynman: The Past and Future Are the Same Thing

The past and future are the same thing | feynman on time symmetry.

Discover one of physics’ most mind-bending secrets: the fundamental laws of nature don’t know which way time flows! In this exploration of Feynman’s ideas on time symmetry, we dive deep into how the equations of physics work equally well forwards and backwards, why positrons are electrons moving backward through time, and how the Wheeler-Feynman absorber theory suggests the future might influence the past.

From billiard balls to quantum mechanics, from Maxwell’s equations to the mystery of why we remember yesterday but not tomorrow, this video unravels the beautiful symmetry hidden beneath our everyday experience of time.

Topics Covered:
• Time symmetry in fundamental physics
• Positrons as electrons traveling backward in time
• Wheeler-Feynman absorber theory
• The thermodynamic arrow of time
• Path integral formulation and quantum mechanics
• Why time appears to flow in one direction
• CP violation and the weak nuclear force.

Perfect for physics enthusiasts, students, and anyone curious about the nature of time and reality.

⚠️ DISCLAIMER: This is AI-generated content created in the style of Richard Feynman’s teaching approach. The script synthesizes information from various sources about Feynman’s work and ideas in theoretical physics, including his lectures, published papers, and documented contributions to quantum electrodynamics and time-symmetric theories. While based on authentic concepts from Feynman’s career, this is an educational interpretation and not actual recorded material from Richard Feynman.

Continue reading “Feynman: The Past and Future Are the Same Thing” | >

Quantum model explains how single electrons cause damage inside silicon chips

Researchers in the UC Santa Barbara Materials Department have uncovered the elusive quantum mechanism by which energetic electrons break chemical bonds inside microelectronic devices—a detrimental process that slowly degrades performance over time. The discovery, published as an Editors’ Suggestion in Physical Review B, explains decades-old experimental puzzles and moves scientists closer to engineering more reliable devices.

Physicists Propose a New Kind of Laser That Would Fire Neutrinos

Physicists have proposed a new way to make neutrinos at accelerated rates. This method would use a state of matter close to absolute zero called a Bose-Einstein condensate. It would harness quantum effects that can produce neutrinos faster than ordinary radioactive decays. This tool would produce a large and controllable beam of neutrinos. They could have similar properties to photons (particles of light) in an optical laser.

Neutrinos are fundamental particles that interact extremely weakly with matter. It is very difficult to produce and detect neutrinos. It requires large detectors and powerful sources such as nuclear reactors or particle accelerators. A controllable, coherent source of neutrinos on a bench-top scale would have a significant impact on neutrino research. This type of technology would provide new opportunities to understand their interactions and quantum mechanical properties. In addition, the specific radioactive decays that would enable such a controllable, coherent neutrino source on a small scale could lead to new applications. These applications could include production of rare isotopes for medical physics and neutrino-based communication.

Lasers have been revolutionary in enabling the development of many aspects of modern science and technology. They are based on the amplification of light via stimulated emission. This is a quantum mechanical process whereby an excited atom is forced to emit a second photon upon absorption of another with the same wavelength. Due to their tiny masses, neutrinos behave similarly to photons in many situations. However, they cannot be used for lasing because their fermionic nature inhibits stimulated emission. For this reason, it is not possible to develop a neutrino laser using this traditional mechanism.

/* */