Science – Page 39 – Investment Policy

Quantum Spin Control: Balancing Speed and Reliability

15.11.2025 by Ray Dalio

$Optimization trajectories, assessed across ten realizations with parameters $N=3$, $T=2$, and $L=8$, demonstrate that local control converges more rapidly and achieves a significantly lower final loss—approximately $2 \times 10^{-4}$—compared to global control, which plateaus around $1.1 \times 10^{-3}$, highlighting the efficiency gains achieved through localized optimization strategies.$

A new variational algorithm optimizes state transfer in complex spin chains, revealing fundamental limits between performance and noise resilience.

The Speed Limit of Quantum Scale-Up

15.11.2025 by Ray Dalio

$Decoding speed, crucial for quantum circuit execution, scales with the number of magic state injections—a relationship assessed at a processor operating point of $d=31$—and ultimately faces a communication latency bottleneck below $10^{-7}$, though the fastest decoder—a custom ASIC—can process circuits with $T\leq 3\times 10^{7}$ within an hour and those with $T\leq 2\times 10^{10}$ within a month, demonstrating a tangible limit to scaling beyond which architectural considerations dominate performance.$

New research reveals that decoding latency and communication bottlenecks pose significant challenges to building larger, more practical quantum computers.

Quantum Words: Encoding Meaning with Near-Term Circuits

14.11.2025 by Ray Dalio

Researchers are exploring how parameterized quantum circuits can create word embeddings that capture semantic relationships, potentially offering advantages over classical methods.

Taming Quantum Noise with Hidden Symmetries

14.11.2025 by Ray Dalio

$Algorithms leveraging metastability demonstrably outperform noise-sensitive approaches by preparing final states, $ \rho_{f}^{N} $, that remain closer to the ideal target state, $ \rho_{f}^{I} $, even under noisy conditions—a critical advantage when achieving a specific final state is paramount.$

New research reveals that quantum noise isn’t always random, and leveraging its predictable, metastable patterns could significantly improve algorithm stability.

Building Blocks for Fault-Tolerant Quantum Computation

14.11.2025 by Ray Dalio

A lift-connected surface code—comprising three interconnected $d=2$ surface codes and utilizing a round-robin logical $H$ gate composed of all-to-all $Y$ interactions and transversal physical $H$ and $Y$ gates—demonstrates a pathway towards fault-tolerant quantum computation through the manipulation of logical $X$ and $Z$ operators supported by distinct qubit arrangements.

Researchers detail a practical approach to constructing universal quantum gates within lift-connected surface codes, bringing scalable error correction closer to reality.

Quantum Limits: Can Error Correction Keep Pace with Catalysis Simulations?

14.11.2025 by Ray Dalio

Catalysis systems exhibit a quantifiable relationship between scalability and space-time volume, with failures – indicated by missing data – occurring when scalability falls below a predetermined minimum threshold for a given system size.

New research reveals that the scalability of fault-tolerant quantum computing presents a significant hurdle for complex simulations, especially in the demanding field of homogeneous catalysis.

Building Tomorrow’s Quantum Computers: A Design Challenge

14.11.2025 by Ray Dalio

As quantum computing moves from theory to practice, a new field—Quantum Design Automation—is emerging to tackle the complex engineering hurdles of building scalable and reliable systems.

Quantum Neural Networks Discern Entangled States with High Fidelity

13.11.2025 by Ray Dalio

A variational quantum classifier, utilizing $n$ qubits, demonstrates a hybrid quantum-classical workflow where quantum computations are seamlessly integrated with classical processing to facilitate pattern recognition.

A novel approach combines the strengths of variational quantum circuits and classical neural networks to accurately classify complex entangled quantum states.

Forged Transactions: Securing Smart Contracts Against Signature Reuse

13.11.2025 by Ray Dalio

The system demonstrates a vulnerability wherein a previously captured, legitimate signature can be replayed to gain unauthorized access, highlighting the inherent fragility of authentication protocols reliant solely on signal reception without considering temporal validity or source verification.

A new analysis reveals how attackers can exploit signature replay vulnerabilities in smart contracts, and introduces a system for automatically detecting these critical flaws.

Smarter Quantum Simulations: A New Encoding Boosts Molecular Accuracy

13.11.2025 by Ray Dalio

Researchers have developed an optimized quantum encoding technique that significantly improves the efficiency and resilience of molecular simulations.