arXiv subjects

Muhammad Noman

Publications and source records attributed to Muhammad Noman.

4 recordsLinked to original sources

arXiv2026

Orthogonality Edges in Strong-Coupling Quantum Work Statistics

Strong coupling to a reservoir can do more than shift, broaden, or dress the work peaks of a driven quantum system. When the reservoir is infrared singular, a sudden change of a local control parameter can alter the boundary condition seen by infinitely many low-energy modes, converting a quasiparticle-like threshold line into a many-body edge. We demonstrate this mechanism for the inclusive work distribution of the biased spin-boson model under a sudden bias inversion. In the independent-boson limit, the problem is exactly solvable and gives a sharp infrared classification: a super-Ohmic bath can retain a finite elastic threshold weight, whereas Ohmic and sub-Ohmic baths extinguish the elastic line through boundary orthogonality. At the Ohmic fixed point, the same exponent controls both the vanishing elastic residue and the low-work continuum. We then ask how this edge is resolved away from the static-boundary limit. Using displaced-basis exact diagonalization of logarithmically discretized baths, we find that finite tunnelling leaves an edge-like continuum over the accessible energy window, while separating two operational diagnostics of the threshold: the cumulative-continuum exponent extracted from $z$-interleaved spectra lies above the elastic-overlap exponent extracted from $z$-averaged overlaps, $\theta_C>\theta_Z$. We interpret this separation as a finite-energy crossover away from the static-boundary fixed point, not as evidence for a new asymptotic fixed point. The separation survives fitting-window variation, oscillator-cutoff checks, spectrum-size checks, and leave-one-$z$-out tests, while time-domain characteristic functions provide a compatible but non-decisive diagnostic. Finally, the same threshold edge controls the sampling cost of Jarzynski-type exponential averages, making rare low-work events increasingly important at low temperature.

quant-ph↗

arXiv2023

Computer Vision-Aided Intelligent Monitoring of Coffee: Towards Sustainable Coffee Production

Coffee which is prepared from the grinded roasted seeds of harvested coffee cherries, is one of the most consumed beverage and traded commodity, globally. To manually monitor the coffee field regularly, and inform about plant and soil health, as well as estimate yield and harvesting time, is labor-intensive, time-consuming and error-prone. Some recent studies have developed sensors for estimating coffee yield at the time of harvest, however a more inclusive and applicable technology to remotely monitor multiple parameters of the field and estimate coffee yield and quality even at pre-harvest stage, was missing. Following precision agriculture approach, we employed machine learning algorithm YOLO, for image processing of coffee plant. In this study, the latest version of the state-of-the-art algorithm YOLOv7 was trained with 324 annotated images followed by its evaluation with 82 unannotated images as test data. Next, as an innovative approach for annotating the training data, we trained K-means models which led to machine-generated color classes of coffee fruit and could thus characterize the informed objects in the image. Finally, we attempted to develop an AI-based handy mobile application which would not only efficiently predict harvest time, estimate coffee yield and quality, but also inform about plant health. Resultantly, the developed model efficiently analyzed the test data with a mean average precision of 0.89. Strikingly, our innovative semi-supervised method with an mean average precision of 0.77 for multi-class mode surpassed the supervised method with mean average precision of only 0.60, leading to faster and more accurate annotation. The mobile application we designed based on the developed code, was named CoffeApp, which possesses multiple features of analyzing fruit from the image taken by phone camera with in field and can thus track fruit ripening in real time.

cs.CV↗

arXiv2021

Effects of classical fluctuating environments on decoherence and bipartite quantum correlations dynamics

We address the time evolution of the quantum correlations ($QCs$) such as entanglement, purity, and coherence for a model of two non-interacting qubits initially prepared as a maximally entangled bipartite state. We contrast the comparative potential of the classical fields to preserve these $QCs$ in the noisy and noiseless realms. We also disclose the characteristic dynamical behavior of the $QCs$ of the two-qubit state under the static noisy effects originating from the common and different configuration models. We show that there is a direct connection between the fluctuations allowed by an environment and the $QCs$ preservation. Due to the static noisy dephasing effects, the $QCs$ are suppressed, resulting in the separability of the two-qubit entangled state after a finite duration. Here, the $QCs$ decay effects are found much smaller in the common configuration model than that of the opponent. Furthermore, this protection of the $QCs$ under static noise for large intervals is entirely attributable to the existence of the entanglement sudden death and birth phenomenon. Most importantly, we found the bipartite $QCs$ less fragile than the tripartite ones in comparison under the static noise. In the case of the measures, the concurrence is found to be sharper for showing the entanglement sudden death and birth revivals in comparison to the purity and decoherence.

quant-ph↗

arXiv2021

To study the structural, electronic and optical properties of predicted stable halide perovskites ABX3

Structure, optical and electronic properties of predicted stables Perovskites ABX3 are calculated using DFT approach. The modified Becke-Johnson potential is also used to investigate electrical and optical properties. The density of states and electronic band structure calculations reveal that the predicted stable halides Perovskites ABX3 have a direct as well as indirect band gap, with dielectric function, optical reflectivity, absorption coefficient, optical conductivity, extinction coefficient, refractive index are calculated in different ranges of energy. The maximum value of static dielectric function is observed for KNiI3 and RbIrBr3 are 3.5 and 3 respectively. The highest absorption peak among the all is observed at 26eV for SrLiF3, while refractive index of that SrLiF3 gives peak at 24eV then refractive index decreases below the unity as energy increases up to 27.5eV. The maximum peaks of optical conductivity of predicted stables halides Perovskites are observed in visible to ultraviolet range (1.7eV to 30eV). The maximum peaks of optical conductivity are observed for SrLiF3 at 24eV. For the first time, all of the properties evaluated for predicted stable halides ABX3Perovskites are reported, because no theoretical work is reported yet on most of the physical properties.

cond-mat.mtrl-sci↗