The copenhagen interpretation & retroactivity. quantum mechanics basics:
Particles exist in a superposition of states until observed.
Measurement “collapses” the wave function into a definite outcome.
Retrocausality Debate:
Some physicists have explored whether quantum events can appear to be influenced by future measurements.
This is sometimes described as the universe “responding retroactively,” but it’s a controversial interpretation, not mainstream science.
Scientists have discovered a new quantum state of matter that connects two significant areas of physics, potentially leading to advancements in computing, sensing and materials science.
A study published in Nature Physics, co-led by Rice University’s Qimiao Si, brings together quantum criticality, where electrons fluctuate between different phases, and electronic topology, which describes a form of quantum organization based on the wave behavior of electrons.
The researchers found that strong interactions among electrons can produce topological behavior, paving the way for new technologies that could use this quantum state in real-world applications.
Neutron scattering and simulations reveal why a promising Kitaev candidate freezes into order instead of forming a quantum spin liquid.
Most magnets are predictable. Cool them down, and their tiny magnetic moments snap into place like disciplined soldiers. However, physicists have long suspected that, under the right conditions, magnetism might refuse to settle even in extreme cold.
This restless state, known as a quantum spin liquid, could unlock new kinds of particles and serve as a foundation for quantum technologies that are far more stable than today’s fragile systems.
At Oak Ridge National Laboratory (ORNL), researchers have now created and closely examined a new magnetic material that brings this strange possibility a little closer to reality, even if it doesn’t quite cross the finish line yet.
Scientists have demonstrated a new method that could allow quantum information to be safely backed up, overcoming one of the longest-standing limitations in quantum computing without violating the fundamental laws that govern quantum systems.
The research describes a way to encode the information contained in a qubit across multiple entangled systems, allowing the original quantum state to be recovered later without directly copying it.
One intriguing method that could be used to form the qubits needed for quantum computers involves electrons hovering above liquid helium. But it wasn’t clear how data in this form could be read easily.
Now RIKEN researchers may have found a solution. Their work is published in the journal Physical Review Letters.
During chemical reactions, atoms in the reacting substances break their bonds and re-arrange, forming different chemical products. This process entails the movement of both electrons (i.e., negatively charged particles) and nuclei (i.e., the positively charged central parts of atoms). Valence electrons are shared and re-arranged between different atoms, creating new bonds.
The movements of electrons and nuclei during chemical reactions are incredibly fast, in many cases only lasting millionths of a billionth of a second (i.e., femtoseconds). Yet reliably tracking and understanding these movements could help to shed new light on how specific molecules are formed, as well as on the underpinnings of quantum mechanical phenomena.
Researchers at Shanghai Jiao Tong University recently introduced a new approach to observe chemical reactions as they unfold, precisely tracking the movement of electrons and atomic nuclei as a molecule breaks apart. This strategy, outlined in a paper published in Physical Review Letters, was successfully used to image the photodissociation of ammonia (NH₃), the process in which a NH₃ molecule absorbs light and breaks down into smaller pieces.
A new framework for understanding the nonmonotonic temperature dependence and sign reversal of the chirality-related anomalous Hall effect in highly conductive metals has been developed by scientists at Science Tokyo. This framework provides a clear picture of the unusual temperature dependence of chirality-driven transport phenomena, forming a foundation for the rational design of next-generation spintronic devices and magnetic quantum materials.
Magnetic materials exhibit a variety of intriguing properties during their magnetization process that reflect their magnetic states and excitations. These properties are studied by applying an external magnetic field to the material, producing the magnetization curve. Magnetic metals additionally demonstrate rich behavior in transport phenomena, referring to the flow of charge, heat, or spin under the influence of magnetic fields.
However, some of these behaviors are difficult to probe using the magnetization curve. The anomalous Hall effect (AHE) is one such effect. In the AHE, when an electric current passes through a magnetic metal, a voltage perpendicular to the current arises even in the absence of an external magnetic field. By contrast, in the traditional Hall effect, such a transverse voltage appears only when an external magnetic field is applied.
Researchers at the Department of Energy’s Oak Ridge National Laboratory are pioneering the design and synthesis of quantum materials, which are central to discovery science involving synergies with quantum computation. These innovative materials, including magnetic compounds with honeycomb-patterned lattices, have the potential to host states of matter with exotic behavior.
Using theory, experimentation and computation, scientists synthesized a magnetic honeycomb of potassium cobalt arsenate and conducted the most detailed characterization of the material to date. They discovered that its honeycomb structure is slightly distorted, causing magnetic spins of charged cobalt atoms to strongly couple and align.
Tuning these interactions, such as through chemically modifying the material or applying a large magnetic field, may enable the formation of a state of matter known as a quantum spin liquid. Unlike permanent magnets, in which spins align fixedly, quantum spins do not freeze in one magnetic state.
Scientists at the X-ray free-electron laser SwissFEL have realized a long-pursued experimental goal in physics: to show how electrons dance together. The technique, known as X-ray four-wave mixing, opens a new way to see how energy and information flow within atoms and molecules. In the future, it could illuminate how quantum information is stored and lost, eventually aiding the design of more error-tolerant quantum devices. The findings are reported in Nature.
Much of the behavior of matter arises not from electrons acting alone, but from the ways they influence each other. From chemical systems to advanced materials, their interactions shape how molecules rearrange, how materials conduct or insulate and how energy flows.
In many quantum technologies —not least quantum computing—information is stored in delicate patterns of these interactions, known as coherences. When these coherences are lost, information disappears—a process known as decoherence. Learning how to understand and ultimately control such fleeting states is one of the major challenges facing quantum technologies today.