arXiv subjects

Neha Yadav

Publications and source records attributed to Neha Yadav.

4 recordsLinked to original sources

arXiv2025

Trapping of electrons and $^{40}\textrm{Ca}^+$ ions in a dual-frequency Paul trap

We demonstrate the operation of a dual-frequency Paul trap and characterize its performance by storing either electrons or calcium ions while applying two quadrupole fields simultaneously which oscillate at $\Omega_\textrm{fast} = 2\pi \times 1.6$ GHz and $\Omega_\textrm{slow} = 2\pi \times 2$ MHz. The particles are loaded and stored in the trap under various conditions followed by detection employing an electron multiplier tube. We find that tens of electrons or ions can be trapped for up to ten milliseconds and a small fraction remains trapped even after hundreds of milliseconds. During dual-frequency operation we find that while the number of trapped electrons rapidly decreases with increase of the $\Omega_\textrm{slow}$ field amplitude, the number of trapped ions shows no dependence on the $\Omega_\textrm{fast}$ field amplitude as supported by our extensive numerical simulations. We aim to use a similar trap for synthesising antihydrogen from antiprotons and positrons. Accordingly, we discuss open challenges such as the co-trapping of oppositely charged species and particle trap duration.

physics.atom-ph↗

arXiv2025

Numerical Investigations of Electron Dynamics in a Linear Paul Trap

Trapped electrons have emerged as an interesting platform for quantum information processing due to their light mass, two-level spin states, and potential for fully electronic manipulation. Previous experiments have demonstrated electron trapping in Penning traps, Paul traps, on solid neon, and superfluid films. In this work, we consider electrons confined in Paul traps, with their spin states as the qubits. For this approach, if the two electrons are trapped in the same potential well, they must form Wigner crystals and remain stable under a static magnetic field to enable two-qubit gates, achievable only within certain trapping parameters. To identify feasible operating conditions, we performed numerical simulations of electron dynamics in linear Paul traps, finding the threshold temperatures required to form two-electron Wigner crystals and studying how the thresholds scale with trap frequencies. In addition, we numerically verified the cooling methods required to reach the crystallization thresholds. Lastly, we examined the stability of electrons under various magnetic field strengths and identified stable regions of trap operation.

quant-ph↗

arXiv2024

GdWN$_3$ is a Nitride Perovskite

Nitride perovskites $AB$N$_3$ are an emerging and highly under-explored class of materials that are of interest due to their intriguing calculated ferroelectric, optoelectronic, and other functional properties. Incorporating novel $A$-site cations is one strategy to tune and expand such properties; for example, Gd$^{3+}$ is compelling due to its large magnetic moment, potentially leading to multiferroic behavior. However, the theoretically predicted ground state of GdWN$_3$ is a non-perovskite monoclinic structure. Here, we experimentally show that GdWN$_3$ crystallizes in a perovskite structure. High-throughput combinatorial sputtering with activated nitrogen is employed to synthesize thin films of Gd$_{1-x}$W$_{x}$N$_{3-y}$ with low oxygen content within the bulk of the films. Ex-situ annealing crystallizes a polycrystalline perovskite phase in a narrow composition window near $x=1$. LeBail fits of synchrotron grazing incidence wide angle X-ray scattering data are consistent with a perovskite ground-state structure. New density functional theory calculations that included antiferromagnetic configurations confirm that the ground-state structure of GdWN$_3$ is a distorted $Pnma$ perovskite with antiferromagnetic ordering, in contrast to prior predictions. Initial property measurements find that GdWN$_3$ is paramagnetic down to $T=2$ K with antiferromagnetic correlations and that the absorption onset depends on cation stoichiometry. This work provides an important stepping stone towards the rapid expansion of the emerging family of nitride perovskites and towards our understanding of their potential multiferroic properties.

cond-mat.mtrl-sci↗

arXiv2023

Probing rotational decoherence with a trapped-ion planar rotor

The quantum rotor is one of the simplest model systems in quantum mechanics, but only in recent years has theoretical work revealed general fundamental scaling laws for its decoherence. For example, a superposition of orientations decoheres at a rate proportional to the sine squared of the angle between them. Here we observe scaling laws for rotational decoherence dynamics for the first time, using a 4-micrometer diameter planar rotor composed of two Paul-trapped ions. We prepare the rotational motion of the ion crystal into superpositions of angular momentum with well-defined differences ranging from 1-3 $\hbar$, and measure the rate of decoherence. We also tune the system-environment interaction strength by introducing resonant electric field noise. The observed scaling relationships for decoherence are in excellent agreement with recent theoretical work, and are directly relevant to the growing development of rotor-based quantum applications.

quant-ph↗