arXiv subjects

S. Saravana Veni

Publications and source records attributed to S. Saravana Veni.

9 recordsLinked to original sources

arXiv2026

Influence of helicoidal spin-orbit coupling and Rabi coupling in dynamics of 2D Bose-Einstein Condensates

This study explores the dynamics of Bose-Einstein condensates (BECs) with helicoidal spin-orbit coupling (SOC) and Rabi coupling, confined under a two-dimensional harmonic potential. The relationship between helicoidal SOC, non-linear interactions along with Rabi coupling and their impact on the stability and non linear trapped modes of the condensate is analyzed using a coupled Gross-Pitaevski (GP) framework. A linearized GP equation is used to investigate modulation instability (MI), demonstrating the impact of strong coupling effects and anisotropic confinement on the instability dynamics. It has been shown that the modulation instability in the condensate is predominantly governed by the competition between the attractive and repulsive mean-field interactions. Additionally, stability regimes are altered by the harmonic confinement, enhancing their susceptibility to SOC-induced asymmetry and intra- and intercomponent interactions. These results shed light on the possibility for unique quantum phases and emergent characteristics of helicoidal SOC-driven condensates.

cond-mat.quant-gas↗

arXiv2026

Characterizing Noise Effects on Multipartite Entanglement via Phase-Space Visualization

This paper investigates the behavior of two fundamental types of multipartite entangled states, namely GHZ(3) and W(3) states under Gaussian-distributed amplitude perturbations and White noise model. The Uhlmann-Jozsa fidelity is taken to be the quantitative measure to show the overall degradation of the quantum states, and is implemented via TQIX : a tool specifically designed for quantum state measurement and related applications. While fidelity analysis captures the progressive decay of quantum states under noise, it offers only limited understanding regarding the state decay and doesn't provide a detailed analysis of how entanglement structures respond to noise models. To reveal the phase-space characteristics and nonclassical signatures of three-qubit entangled states, we employ the spin Wigner function using equal-angle projection. This approach reveals a continuous fading of quantum coherence with increasing noise strength, ultimately providing a clear picture of transition toward classical-like behavior in phase space. This combined qualitative-quantitative framework provides deeper understanding of how different entanglement structures respond to noise, offering practical applications for designing and implementing noise resilient protocols in quantum computing, and quantum information processing.

quant-ph↗

arXiv2026

First- and Second-Order Digital Quantum Simulation of Three-Level Jaynes-Cummings Dynamics on Superconducting Quantum Processors

This work presents a digital quantum simulation of a three-level atomic system interacting with a single-mode electromagnetic field based on the Jaynes-Cummings model, implemented on IBM Quantum superconducting processors. A qutrit is encoded using two physical qubits to represent the atomic states, while an additional qubit encodes the truncated field mode, enabling the realization of effective $Λ$-type atomic dynamics.The continuous-time light-matter interaction is implemented in a digital form by discretizing the evolution using Suzuki-Trotter decomposition. In contrast to an analog realization, the digital simulation replaces the continuous evolution with a sequence of quantum gates whose parameters are explicitly controlled. Phase evolution arising from the interaction Hamiltonian is digitally encoded using calibrated $R_Z$ gates, whose rotation angles are fixed by the physically relevant coupling scale and the chosen Trotter time step.State preparation is achieved using Hadamard and parametrized rotation gates, while the interaction dynamics are implemented through controlled operations. A comparative analysis between first- and second-order Trotter implementations reveals a trade-off between digital accuracy and hardware-induced noise. Overall, the results demonstrate that calibrated gate operations and noise-aware circuit design enable reliable digital simulation of multi-level light-matter interactions on noisy intermediate-scale quantum platforms.

quant-ph↗

arXiv2026

Toroidal Confinement and Beyond: Vorticity-Defined Morphologies of Dipolar $^{164}$Dy Quantum Droplets

We investigate the formation, stability, and dynamics of 3D ring-shaped and multipole vortical quantum droplets (QDs) in non-rotating dipolar Bose-Einstein condensates held in a toroidal trapping potential. The QD dynamics are investigated in the framework of the extended Gross-Pitaevskii equation, which includes long-range dipole-dipole interactions (DDI) and the beyond-mean-field Lee-Huang-Yang (LHY) term, revealing the emergence of self-bound states. Stable stationary solutions for multipole QDs with different values of the topological charge (vorticity $S$) are shaped as necklace-like modes, with the number of \textquotedblleft beads" (multipole's order) $n=2S$, up to $S=6$. The stability area of the multipoles shrinks with the increase of $S$. For higher values of $S$ the centrifugal effect associated with the phase winding destabilizes the annular density and drives the formation of fragmented multipole droplet states. The dependence of the chemical potential, total energy and peak density on the norm (number of particles) and $S$ is produced. These findings uncover the stabilizing effect of the LHY correction and DDI anisotropy in maintaining complex QD states in the non-rotating configurations.

cond-mat.quant-gas↗

arXiv2025

Exploring Satellite Quantum Key Distribution under Atmospheric Constraints

Satellite Quantum Key Distribution creates a pathway for secure global communication with a level of security that is peerless. However, ground-to-satellite Quantum Key Distribution links are degraded due to the atmospheric turbulence. This paper gives a numerical framework using angular spectrum propagation, Hufnagel-Valley model of turbulence and Von Karman phase screens and takes into account the static losses introduced due to the absorption of the beam by the different elements and compounds in the atmosphere like O2, CO2 and H2O. This simulation propagates a Gaussian beam step by step through the atmosphere, where we incorporate the phase distortions using phase screens based on standard Cn2 profiles which take into account losses such as scintillation and beam wander. We simulate the BB84 protocol with decoy states for added security. The results of the simulation quantify the expected link budget and Secure key rates over a range of distances to measure the viability of Free Space Optical Quantum Key Distribution links at different distances.

quant-ph↗

arXiv2025

Quantum Circuit Benchmarking on IBM Brisbane: Performance Insights from Superconducting Qubit Models

This paper investigates quantum communication using superconducting qubits, emphasizing the simulation and control of quantum systems via IBM Brisbane quantum processor. We focus on implementing fundamental quantum gates and analyzing the evolution of entangled states, which are essential for secure and reliable information transfer. The study highlights the role of entanglement as a critical resource in quantum communication, enabling secure connectivity across quantum networks. Simulations incorporate realistic conditions, including decoherence and noise, to assess the practical viability of entangled state operations. Additionally, we explore the extension of these systems to simulate key quantum models such as the Jaynes Cummings and longitudinal Ising models, offering insight into complex interactions in superconducting architectures. The findings advance quantum information science by demonstrating the potential of superconducting qubit systems for both foundational research and real world applications in quantum communication.

quant-ph↗

arXiv2025

Material-Driven Optimization of Transmon Qubits for Scalable and Efficient Quantum Architectures

One of the most crucial steps in creating practical quantum computers is designing scalable and efficient superconducting qubits. Coherence times, connections between individual qubits, and reduction of environmental noise are critical factors in the success of these qubits. Because they can be lithographically fabricated and are less sensitive to charge noise, superconducting qubits, especially those based on the Transmon architecture, have emerged as top contenders for scalable platforms. In this work, we use a combination of design iteration, material analysis, and simulation to tackle the superconducting qubit optimization challenge. We created transmon-based layouts for 4 qubits and 8 qubits using Qiskit Metal and conducted an individual analysis for each qubit. We investigated anharmonicity and extracted eigenfrequencies, computing participation ratios across several design passes, and identifying the top five energy eigenstates using Ansys HFSS. We then created a 2D cross section of a single qubit design in COMSOL Multiphysics to evaluate how different materials affect performance. This enables us to assign various superconducting materials and substrates and investigate their effects on energy loss and electromagnetic properties. Qubit coherence and overall device quality are significantly influenced by the materials chosen. This integrated framework of material based simulation and circuit design offers a workable way to create reliable superconducting qubit systems and supports continued attempts to create scalable, fault-tolerant quantum computing.

quant-ph↗

arXiv2025

Synergistic Effects of Spin-Orbit Coupling and Intercomponent Interactions in Two-Component (2+1)D Photonic Fields

The study investigates the formation, stability and dynamic advancement of two-dimensional vortex quantum droplets within binary Bose-Einstein condensates (BECs), shaped by the interplay of photonic spin-orbit coupling (SOC) and quantum fluctuation effects. SOC leads to significant droplet stretching, resulting in vortex clusters forming in each component. The competition between photonic SOC and Lee-Huang-Yang (LHY) interactions introduces vortices into the condensate, described by the numerically solved Gross-Pitaevskii equation (GPE). The results show that droplets like structures arise at low SOC strengths and interaction parameters. The transition to vortex takes place as the SOC increases. Enhanced interactions give rise to the emergence of quantum droplets as the vortices dissipate, demonstrating fascinating dynamics. These findings enhance understanding of the physical properties of photonic SOC coupled binary BECs in 2D with LHY correction, impacting cold-atom physics and condensed matter research. The study can also be expanded to explore quantum droplets with a small atom count, which is advantageous for experimental applications.

cond-mat.quant-gas↗

arXiv2025

Vortex droplets and lattice patterns in two-dimensional traps: A photonic spin-orbit-coupling perspective

In the context of the mean-field exciton-polariton (EP) theory with balanced loss and pump, we investigate the formation of lattice structures built of individual vortex-antivortex (VAV) bound states under the action of the two-dimensional harmonic-oscillator (HO) potential trap and effective spin-orbit coupling (SOC), produced by the TE-TM splitting in the polariton system. The number of VAV elements (pixels) building the structures grow with the increase of self- and cross-interaction coefficients. Depending upon their values and the trapping frequency, stable ring-shaped, circular, square-shaped, rectangular, pentagonal, hexagonal, and triangular patterns are produced, with the central site left vacant or occupied in the lattice patterns of different types. The results suggest the experimental creation of the new patterns and their possible use for the design of integrated circuits in EP setups, controlled by the strengths of the TE-TM splitting, nonlinearity, and HO trap.

physics.optics↗