Science – Page 7

Mapping the Milky Way’s Dark Side

06.12.2025 by pricpr

New simulations and machine learning techniques are refining our understanding of dark matter’s distribution within our galaxy, paving the way for more sensitive direct detection experiments.

Beyond the Limits of Quantum Coherence

06.12.2025 by pricpr

New research explores the surprising potential for amplifying a fragile quantum property, and defines the boundaries of its enhancement under realistic constraints.

Beyond Equilibrium: Universal Signatures of Quantum Phase Transitions

06.12.2025 by pricpr

$The study of the dissipative Dicke model reveals that near the critical point, the thermodynamic metric $ζ$ scales according to $ζ \sim |g - g_{c}|^{x}$, with a numerically determined exponent of $x = -2.9953 \pm 0.0009$ - a value remarkably consistent with the theoretical prediction of $x = -(\alpha + \gamma)$, given parameters $\alpha = 2$ and $\gamma = 1$.$

New research reveals a unifying principle governing how quantum systems transition between phases, even when driven far from equilibrium.

Beyond Hermiticity: A Dissipative Spin Liquid Model Unveiled

06.12.2025 by pricpr

$The study demonstrates that the Liouvillian spectrum-analyzed for systems with linear sizes ranging from 4 to 64-reveals a phase transition point, $\gamma_{PT}$, which scales inversely with system size ($1/L$), while a critical value, $\gamma^*$, remains approximately constant at $3J/4$, and the fraction of broken $\mathcal{PT}$ symmetry smoothly transitions from 0 to 1 as the parameter $\gamma$ crosses these thresholds.$

Researchers have discovered an exactly solvable model demonstrating how non-Hermitian dynamics can give rise to exotic quantum phenomena in dissipative spin liquids.

When Perturbation Fails: Taming Light in Complex Cavities

06.12.2025 by pricpr

$A ring cavity, incorporating a dispersing medium, modulates the propagation of a pulsed light field $E_i(t,z)$ pumped through an input-output mirror with reflection coefficient $\sqrt{\mathcal{R}}$ and transmission coefficient $\sqrt{\mathcal{T}}$, effectively creating a round-trip time $T_{R}$ that governs the cavity’s dispersive response.$

A new analysis reveals the limits of simplified modeling techniques used to predict how light pulses behave within dispersive optical cavities.

Smarter Inference: Guiding Language Models with Real-Time Rewards

06.12.2025 by pricpr

A new approach selectively builds upon promising generations during inference, boosting performance beyond traditional methods.

Bridging Microwaves and Light: A New Path to Quantum Networks

06.12.2025 by pricpr

Researchers demonstrate a promising pump-free method for converting microwave signals into optical photons, a critical step towards building long-distance quantum communication systems.

Untangling Qubit Control: A Bayesian Approach

06.12.2025 by pricpr

$Stepwise two-parameter estimation, utilizing prior distributions with a width of $5^{\circ}$, demonstrates that the accuracy of shift estimation-indicated by a standard deviation of $\Delta\gamma$-approaches the classical Van Trees limit as a function of angle $\theta$, while axis estimation accuracy, similarly assessed with $\Delta\theta$, closely aligns with the theoretical prediction and remains consistent with the diagonal, signifying effective parameter recovery.$

New research explores a practical method for precisely calibrating multiple qubit rotations using Bayesian inference.

Simulating the Universe’s Instability: A Quantum Leap for Vacuum Decay Studies

06.12.2025 by pricpr

A programmable Rydberg atom array simulates the decay of a false vacuum, mirroring the behavior of an antiferromagnetic Ising model where staggered detuning creates a metastable state susceptible to quantum tunneling and the nucleation of true vacuum bubbles, effectively demonstrating a physical analogue of vacuum instability.

Researchers have successfully used a programmable array of Rydberg atoms to model the process of false vacuum decay, offering a new platform to explore fundamental questions about the stability of the universe.

Taming the Unstable: Universal Control of Quantum Systems

05.12.2025 by pricpr

$Through manipulation of a $PT$-symmetric Hamiltonian within a cavity-magnonic system, Fock-state transfer-specifically transitioning from $|5\rangle_a|0\rangle_b$ to $|0\rangle_a|5\rangle_b$-demonstrates fidelity regardless of whether exceptional points are avoided or crossed, a result achieved by dynamically constraining coherent coupling strength $J(t)$ and detuning $\Delta(t)$ via a time-dependent parameter $\theta(t)$, and ensuring the preservation of initial and final state differences $f_i(\tau) - f_i(0) = 0$ under conditions where $\varphi_a = \pi$, $\varphi = \pi/2$, $\Gamma = 0$, and $\gamma_a = \gamma_b$ satisfies a defined relationship with $\lambda$ dependent on whether exceptional points are avoided ($\lambda = \pi$) or crossed ($\lambda = 4\pi$).$

Researchers have developed a new framework for controlling non-Hermitian quantum systems, overcoming limitations imposed by their inherent instability.