Beyond Markov: A New Approach to Quantum System Dynamics
![The dynamics of a spin-boson system-characterized by a spin interacting with a harmonic bath, and defined by parameters [latex]\omega_s = 2[/latex], [latex]\Omega = 1[/latex], [latex]\beta = 2[/latex], [latex]\lambda = 0.2[/latex], and [latex]\omega_C = 5[/latex]-reveal the time evolution of both population and coherence, calculated via a [9/16] Padé approximant to model the system’s memory kernel.](https://arxiv.org/html/2603.01458v1/2603.01458v1/x1.png)
Researchers have developed an extension to memory kernel coupling theory that dramatically improves the simulation of complex, interacting quantum systems over time.
Science
Seeking the Unexpected: AI Agents Learn to Explore Through Future Prediction
New research demonstrates a method for training artificial intelligence to explore environments effectively without external rewards by focusing on the unpredictability of future states.
Shining a Light on Quantum Collective Behavior
![Quantum systems reveal that collective spin behavior is profoundly shaped by particle statistics, transitioning from a fully symmetric state at full inversion to differentiated spin shells for bosons and fermions at zero temperature, and ultimately converging towards indistinguishability at sufficiently high temperatures where exchange symmetry loses relevance-a phenomenon described by the relationship [latex]S=|\mathcal{N}^{(e)}-\mathcal{N}^{(g)}|/2[/latex] for fermionic spin shells.](https://arxiv.org/html/2603.00778v1/2603.00778v1/x3.png)
New research explores how the fundamental properties of matter at extremely low temperatures influence the way light is emitted and amplified.
Hunting Hidden Particles with Light
![An experiment seeks to produce dark photons through the collision of a 3 GeV electron beam with a laser operating at the [latex]\mathcal{O}(\mathrm{eV})[/latex] scale, while X-ray detectors primarily register background photons-a signature indicative of the challenge in isolating these elusive particles.](https://arxiv.org/html/2603.00247v1/2603.00247v1/x6.png)
A new experiment leveraging electron-photon collisions aims to reveal the elusive nature of dark photons and other particles from the hidden sector.
Beyond Locality: Algebra and the Limits of Quantum Correlation
New research explores how the mathematical structure of quantum systems determines the strength of their non-local connections, revealing conditions for maximal Bell inequality violation.
Rewiring Superconductivity: Patterning Reveals Hidden States in Nickelate Films
Researchers have demonstrated that precisely controlling the phase of superconductivity in nickelate materials through nano-patterning can induce unusual metallic behavior and reverse the material’s directional superconducting properties.
Silicon’s Hidden Form: Unlocking the Mystery of Si-XIII
![Silicon’s transition between the Si-XIII phase and its more stable, metastable counterparts-including BC8, R8, and the [latex]d_c[/latex] and [latex]h_d[/latex] phases-is not singular, but rather unfolds along multiple minimum energy pathways, as determined by Solid State Nudged Elastic Band calculations, suggesting a complex energy landscape governing phase transformations in this foundational material.](https://arxiv.org/html/2602.24248v1/2602.24248v1/x4.png)
After decades of pursuit, researchers have finally determined the precise atomic structure of the elusive Si-XIII phase of silicon, resolving a long-standing challenge in materials science.
Unveiling the Electronic Landscape of an Altermagnet
![CrSb exhibits altermagnetic behavior, evidenced by band structure calculations - incorporating spin-orbit coupling via VASP - that reveal shifts in Fermi surfaces ([latex]FSs[/latex]) related to internal field effects and localized spin polarization ([latex]S\_z[/latex]) along the [latex]c[/latex]-axis, as visualized within the first Brillouin zone.](https://arxiv.org/html/2602.24033v1/2602.24033v1/x5.png)
New measurements of the material CrSb reveal a complex Fermi surface and confirm its unique altermagnetic properties, offering insights into this emerging class of magnetic materials.
Machine Learning Accelerates the Search for New Materials
A new study benchmarks the accuracy and efficiency of machine learning potentials for predicting stable crystal structures, paving the way for faster materials discovery.
Warped Realities: How Cosmic Defects Shape Quantum Fields
New research explores how the interplay of cosmic strings, global monopoles, and the principles of Rainbow Gravity alter the behavior of scalar bosons at the quantum level.