arXiv subjects

Marius Romuald Kamsap

Publications and source records attributed to Marius Romuald Kamsap.

6 recordsLinked to original sources

arXiv2026

Shortcut to Adiabatic Transfer in a Four-Level N-type System using Counterdiabatic Driving

The stimulated Raman shortcut-to-adiabatic passage (STIRSAP) technique has been demonstrated to accelerate adiabatic population transfer processes. Traditionally applied to three-level atomic systems, this method enables rapid and efficient population transfer in a short interaction time. In this work, we extend this approach to a four-level N -type system driven by three laser fields. Under the three-photon phase matching condition, the first-order Doppler effect can be completely eliminated, making this configuration more suitable for applications in frequency metrology and quantum information processing. By adiabatically eliminating the intermediate state, the four-level system is effectively reduced to a two-level model, enabling the application of counterdiabatic driving without requiring additional couplings. This approach allows for fast and efficient population transfer between metastable states. We analyze the influence of laser intensity peaks and detuning, and we show that the transfer time is significantly shorter than that achieved with the STIRAP technique. Moreover, we also show 1 that an optimal coupling strength between the ground and metastable states further minimizes the operation time.

physics.atom-ph↗

arXiv2026

A linear Paul trap to study the equilibrium of charged micron-sized particles in air

We describe and use a macroscopic linear quadrupolar trap to explore the trapping and equilibrium properties of charged particles. These devices, when operated to trap atomic ions, are at the core of ion based quantum computer and optical atomic clock. To illustrate the characteristics of few particle trapping, and observe different force balance on a charged particle, a macroscopic linear trap, operating at room condition, is trapping micrometer-sized particles. Compared to atomic or molecular ions, their mass can not be neglected and requires an extra voltage for gravity force compensation. We show how this compensation can be demonstrated experimentally and that the choice of hollow-core glass spheres has the advantage of a good reproducibility of the experiments, that allows one to deduce with good precision the charge-to-mass ratio of the trapped particle.

physics.ins-det↗

arXiv2016

Experimental demonstration of an efficient number diagnostic for long 1D ion chains

Very long, one-dimensional (1D) ion chains are the basis for many applications, in particular in quantum information processing and reliable diagnostics are needed to quantify them. To that purpose, we have experimentally validated Dubin's model for very long ion chains [Phys. Rev. Lett. 71, 2753 (1993)]. This diagnostic allows to precisely determine the number of trapped ion with an accuracy of almost 1\% without counting them, by measuring the ion-ion distance of the innermost particles, as well as the trapping potential along the ion chain direction. In our experiment, based on a 155 ion chain, the central 30 ions are measured to be equidistant to better than 2\%, and we can determine the total number of trapped ions with a 4.5\% uncertainty, completely dominated by a conservative estimation of the experimental characterisation of the trap.

quant-ph↗

arXiv2015

Fast and efficient transport of large ion clouds

The manipulation of trapped charged particles by electric fields is an accurate, robust and reliable technique for many applications or experiments in high-precision spectroscopy. The transfer of the ion sample between multiple traps allows the use of a tailored environment in quantum information, cold chemistry, or frequency metrology experiments. In this article, we experimentally study the transport of ion clouds of up to 50 000 ions. The design of the trap makes ions very sensitive to any mismatch between the assumed electric potential and the actual local one. Nevertheless, we show that being fast (100 $μ$s to transfer over more than 20 mm) increases the transport efficiency to values higher than 90 %, even with a large number of ions. For clouds of less than 2000 ions, a 100 % transfer efficiency is observed.

physics.plasm-ph↗

arXiv2014

Ion transport in macroscopic RF linear traps

Efficient transport of cold atoms or ions is a subject of increasing concern in many experimental applications reaching from quantum information processing to frequency metrology. For the scalable quantum computer architectures based on the shuttling of individual ions, different transport schemes have been developed, which allow to move single atoms minimizing their energy gain. In this article we discuss the experimental implementation of the transport of a three-dimensional ion cloud in a macroscopic linear radiofrequency (RF) trap. The present work is based on numerical simulations done by molecular dynamics taking into account a realistic experimental environment. The deformation of the trapping potential and the spatial extension of the cloud during transport appears to be the major source of the ion energy gain. The efficiency of transport in terms of transfer probability and ion number is also discussed.

physics.atom-ph↗

arXiv2013

Coherent internal state transfer by three-photon STIRAP-like scheme for many-atom samples

A STIRAP-like scheme is proposed to exploit a three-photon resonance taking place in alkaline-earth-metal ions. This scheme is designed for state transfer between the two fine structure components of the metastable D-state which are two excited states that can serve as optical or THz qu-bit. The advantage of a coherent three-photon process compared to two-photon STIRAP lies in the possibility of exact cancellation of the first order Doppler shift which opens the way for an application to a sample composed of many ions. The transfer efficiency and its dependence with experimental parameters are analyzed by numerical simulations. This efficiency is shown to reach a fidelity as high as $(1-8.10^{-5})$ with realistic parameters. The scheme is also extended to the synthesis of a linear combination of three stable or metastable states.

quant-ph↗