arXiv subjects

Partha Sarker

Publications and source records attributed to Partha Sarker.

5 recordsLinked to original sources

arXiv2026

Exchange-frustrated quadrupoles on the honeycomb lattice: Flavor-wave spectra, classical degeneracies and parton constructions

We study the quadrupolar Kitaev model, an $S=1$ honeycomb-lattice model with frustrated bond-dependent quadrupolar interactions. Using complementary methods and expanding around controlled limits, we uncover several intertwined structures. First, a semiclassical variational analysis based on $\mathrm{SU}(3)$ flavor theory reveals an extensively degenerate manifold of classical mean-field ground states, suggesting that quantum fluctuations may stabilize a quantum-disordered phase. Second, in the bond-anisotropic limit, perturbation theory is used to derive effective low-energy Hamiltonians, which crucially depend on the presence (or absence) of a residual symmetry $\mathcal{M}$ of combined lattice reflection and discrete spin rotation. A Majorana parton construction uncovers an exact $\mathbb Z_2$ gauge structure and motivates possible confined and deconfined phases driven by gauge-charge condensation, consistent with the effective theories obtained in anisotropic limit. Further, within the same parton formalism, different Majorana mean-field ans\"atze produce both gapless and gapped candidate quantum-disordered states, distinguished by linear versus projective implementations of $\mathcal M$. Our results highlight frustrated quadrupolar interactions as a route to quantum-disordered phases, relevant to $S \geq 1$ Kitaev materials and Rydberg-array quantum simulators.

cond-mat.str-el↗

arXiv2025

Multi-Level Embedding Conformer Framework for Bengali Automatic Speech Recognition

Bengali, spoken by over 300 million people, is a morphologically rich and lowresource language, posing challenges for automatic speech recognition (ASR). This research presents an end-to-end framework for Bengali ASR, building on a Conformer-CTC backbone with a multi-level embedding fusion mechanism that incorporates phoneme, syllable, and wordpiece representations. By enriching acoustic features with these linguistic embeddings, the model captures fine-grained phonetic cues and higher-level contextual patterns. The architecture employs early and late Conformer stages, with preprocessing steps including silence trimming, resampling, Log-Mel spectrogram extraction, and SpecAugment augmentation. The experimental results demonstrate the strong potential of the model, achieving a word error rate (WER) of 10.01% and a character error rate (CER) of 5.03%. These results demonstrate the effectiveness of combining multi-granular linguistic information with acoustic modeling, providing a scalable approach for low-resource ASR development.

eess.AS↗

arXiv2025

A Notification Based Nudge for Handling Excessive Smartphone Use

Excessive use of smartphones is a worldwide known issue. In this study, we proposed a notification-based intervention approach to reduce smartphone overuse without making the user feel any annoyance or irritation. Most of the work in this field tried to reduce smartphone overuse by making smartphone use more difficult for the user. In our user study (n = 109), we found that 19.3% of the participants are unwilling to use any usage-limiting application because a) they do not want their smartphone activities to get restricted or b) those applications are annoying. Following that, we devised a hypothesis to minimize smartphone usage among undergraduates. Finally, we designed a prototype for Android, "App Usage Monitor," and conducted a 3-week experiment through which we found proof of concept for our hypothesis. In our prototype, we combined techniques such as nudge and visualization to increase self-awareness among the user by leveraging notifications.

cs.HC↗

arXiv2022

Circuit Complexity in $\mathcal{Z}_{2}$ ${\cal EEFT}$

Motivated by recent studies of circuit complexity in weakly interacting scalar field theory, we explore the computation of circuit complexity in $\mathcal{Z}_2$ Even Effective Field Theories ($\mathcal{Z}_2$ EEFTs). We consider a massive free field theory with higher-order Wilsonian operators such as $ϕ^{4}$, $ϕ^{6}$ and $ϕ^8.$ To facilitate our computation we regularize the theory by putting it on a lattice. First, we consider a simple case of two oscillators and later generalize the results to $N$ oscillators. The study has been carried out for nearly Gaussian states. In our computation, the reference state is an approximately Gaussian unentangled state, and the corresponding target state, calculated from our theory, is an approximately Gaussian entangled state. We compute the complexity using the geometric approach developed by Nielsen, parameterizing the path ordered unitary transformation and minimizing the geodesic in the space of unitaries. The contribution of higher-order operators, to the circuit complexity, in our theory has been discussed. We also explore the dependency of complexity with other parameters in our theory for various cases.

hep-th↗

arXiv2022

Entanglement in interacting quenched two-body coupled oscillator system

In this work, we explore the effects of a quantum quench on the entanglement measures of a two-body coupled oscillator system having quartic interaction. We use the invariant operator method, under a perturbative framework, for computing the ground state of this system. We give the analytical expressions for the total and reduced density matrix of the system having non-Gaussian, quartic interaction terms. Using this reduced density matrix, we show the analytical calculation of two entanglement measures viz., Von Neumann entanglement entropy using replica trick and Renyi entanglement entropy. Further, we give a numerical estimate of these entanglement measures with respect to the dimensionless parameter $(t/δt$) and show its behaviour in the three regimes, i.e; late time behaviour, around the quench point and the early time behaviour. We comment on the variation of these entanglement measures for different orders of coupling strength. The variation of Renyi entropy of different orders has also been discussed.

hep-th↗