This collection develops a connected research program: coherence-limited sensing, channel precision laws, degree-of-freedom-resolved noise, information redistribution, and network-level quantum behavior.
Quantum Research · Deepinder Sidhu · 2026
Quantum decoherence is traditionally modeled through empirical decay laws in which observable coherence decreases with time. While these models successfully describe the dynamics of open quantum systems, they do not by themselves explain the physical destination of the apparently lost coherence. Motivated by the Structured Quantum Noise (SQN) framework, which models noise as a structured quantum subsystem rather…
Research BriefDownload PDFQuantum Research · Deepinder Sidhu · 2026
Quantum sensing platforms—including optical interferometers, atomic and ion clocks, NV-center magnetometers, and superconducting-qubit sensors—aspire to Heisenberg-limited precision, yet all exhibit an unavoidable breakdown of this scaling under realistic noise. Building on the Heisenbergsaturation framework introduced in earlier work, we present a universal cross-platform law that captures this breakdown in a…
Research BriefDownload PDFQuantum Research · Deepinder Sidhu · 2026
Quantum metrology promises Heisenberg-limited precision, yet every practical platform exhibits a breakdown of this scaling as resources increase. We present a compact, platform-independent framework in which the total sensing resource is decomposed as N = M L, where M denotes the number of probes interrogated in parallel and L denotes the coherent sequential interrogation depth. Under realistic decoherence,…
Research BriefDownload PDFQuantum Research · Deepinder Sidhu · 2026
Dynamic Quantum Resource Partitioning Architecture (DQRPA) provides a system-level framework for operating quantum-enhanced systems under realistic noise and coherence constraints. Rather than relying on monolithic entangled states whose performance collapses outside laboratory conditions, DQRPA partitions a fixed resource budget into coherence-matched logical blocks, selected by maximizing the retained Heisenberg…
Research BriefDownload PDFQuantum Research · Deepinder Sidhu · 2026
Structured Quantum Noise (SQN) models environmental noise as a structured quantum process rather than as scalar attenuation alone. Previous work established the mathematical framework for SQN and demonstrated its implications for coherence redistribution and quantum decoherence. This paper addresses a different question: whether Quantum Field Theory (QFT) and vacuum fluctuations provide a physically motivated…
Research BriefDownload PDFQuantum Research · Deepinder Sidhu · 2026
Quantum channels inevitably degrade coherence and thereby reshape the precision scaling predicted by ideal Heisenberg limits. Rather than attributing this reduction to probe choice, measurement strategy, or architectural details, we present a compact, channel-centric framework in which the impact of noise is captured by a single coherence function governing an L-fold coherent interrogation. Within this formulation,…
Research BriefDownload PDFQuantum Research · Deepinder Sidhu · 2026
Structured Quantum Noise (SQN) models environmental interactions as structured quantum dynamics in an enlarged Hilbert space rather than as scalar attenuation alone. Prior work extended SQN to quantum-switched optical networks by assigning structured noise maps to communication links and Bell-state-measurement maps to switching nodes. This paper extends that formulation by treating practical photonic network…
Research BriefDownload PDFQuantum Research · Deepinder Sidhu · 2026
This paper presents a mathematical framework for incorporating Structured Quantum Noise (SQN) into quantum-switched optical networks. SQN is represented as a link-level quantum operation, while Bell-state-measurement-based entanglement swapping is represented as a switching operation. Single-switch, two-switch, and general N -switch network architectures are derived explicitly. The resulting ordered-composition…
Research BriefDownload PDFQuantum Research · Deepinder Sidhu · 2026
Quantum noise is usually represented as a completely positive trace-preserving map acting on an observed subsystem. This representation is operationally useful, but it can suppress the physical structure of the environment that generates the apparent decoherence. Independent Markovian noise primarily attenuates coherence and distinguishability. Structured environments, by contrast, may contain retained degrees of…
Research BriefDownload PDF