Related papers: Sympathetic ground state cooling and coherent mani…
We propose a novel cooling scheme for realising single photon sideband cooling on particles trapped in a state-dependent optical potential. We develop a master rate equation from an ab-initio model and find that in experimentally feasible…
Control of the external degree of freedom of trapped molecular ions is a prerequisite for their promising applications to spectroscopy, precision measurements of fundamental constants, and quantum information technology. Here, we…
Trapped ion in the Lamb-Dicke regime with the Lamb-Dicke parameter $\eta\ll1$ can be cooled down to its motional ground state using sideband cooling. Standard sideband cooling works in the weak sideband coupling limit, where the sideband…
Doppler cooling with lasers is essential to ions' trapping and also a preliminary step towards achievement of ultracold ions. Due to lack of effective tools, experimentally monitoring the ions' temperature and the laser-ion coupling is…
A prerequisite for laser cooling a molecular anion, which has not been achieved so far, is the precise knowledge of the relevant transition frequencies in the cooling scheme. To determine these frequencies we present a versatile method that…
This paper analyses the cooling of a single particle in a harmonic trap with red-detuned laser light with fewer approximations than previously done in the literature. We avoid the adiabatic elimination of the excited atomic state but are…
We propose a new concept for a two-qubit gate operating on a pair of trapped ions based on laser coherent control techniques. The gate is insensitive to the temperature of the ions, works also outside the Lamb-Dicke regime, requires no…
We report on the construction and characterization of an apparatus for quantum information experiments using $^{88}$Sr$^+$ ions. A miniature linear radio-frequency (rf) Paul trap was designed and built. Trap frequencies above 1 MHz in all…
We demonstrate a new temperature record for image-current mediated sympathetic cooling of a single proton in a cryogenic Penning trap by laser-cooled $^9$Be$^+$. An axial mode temperature of 170 mK is reached, which is a 15-fold improvement…
Optically trapped dielectric objects are well suited for reaching the quantum regime of their center of mass motion in an ultra-high vacuum environment. We show that ground state cooling of an optically trapped nanosphere is achievable when…
We propose a new way for sympathetic cooling of ions in an electromagnetic Paul trap: it implies the use for this purpose of cold buffer atoms in the region of atom-ion confinement-induced resonance (CIR). The problem is that the…
We developed a surface-electrode ion trap with a square hole measuring $40\,\mathrm{\mu m}$ for atomic loading. The hole was fabricated using anisotropic etching of a silicon substrate and was designed to minimize potential distortion in…
We investigate the problem of a single ion in a radio-frequency trap and immersed in an ultracold Bose gas either in a condensed or a non-condensed phase. We develop master equation formalism describing the sympathetic cooling and we…
Motional ground state cooling and internal state preparation are important elements for quantum logic spectroscopy (QLS), a class of quantum information processing. Since QLS does not require the high gate fidelities usually associated with…
We have performed a detailed experimental study of resistive cooling of large ensembles of highly charged ions such as Ar$^{13+}$ in a cryogenic Penning trap. Different from the measurements reported in [M. Vogel et al., Phys. Rev. A,…
We present a new technique for cooling arbitrary charged particles in a Penning trap by utilizing self-cooled electrons stored in a separate, macroscopically distant Penning trap as the cooling medium. The electrons decay predominantly to…
We developed a multi-mode ground state cooling technique based on electromagnetically-induced transparency (EIT). By involving an additional ground and excited state, two individually adjustable bright states together with a dark state are…
We provide a general framework to describe cooling of a micromechanical oscillator to its quantum ground state by means of radiation-pressure coupling with a driven optical cavity. We apply it to two experimentally realized schemes,…
Planar thermal equilibration is studied using direct numerical simulations of ultracold two-dimensional (2D) ion crystals in a Penning trap with a rotating wall. The large magnetic field of the trap splits the modes that describe in-plane…
We report on a cycling scheme for Doppler cooling of trapped OH$^+$ ions using transitions between the electronic ground state $X^3\Sigma^-$ and the first excited triplet state $A^3\Pi$. We have identified relevant transitions for photon…