A5079767257- Advanced Frequency and Time Standards
- Cold Atom Physics and Bose-Einstein Condensates
- Atomic and Subatomic Physics Research
- Advanced Fiber Laser Technologies
- Scientific Measurement and Uncertainty Evaluation
- Quantum optics and atomic interactions
- Mechanical and Optical Resonators
- Quantum Information and Cryptography
- Atomic and Molecular Physics
- Force Microscopy Techniques and Applications
- Spectroscopy and Quantum Chemical Studies
- Ion-surface interactions and analysis
- Radioactive Decay and Measurement Techniques
- Cardiovascular Syncope and Autonomic Disorders
- Quantum Mechanics and Applications
- Diamond and Carbon-based Materials Research
- nanoparticles nucleation surface interactions
- Hemodynamic Monitoring and Therapy
- Noncommutative and Quantum Gravity Theories
- Laser-Matter Interactions and Applications
- Mass Spectrometry Techniques and Applications
- Thermal properties of materials
- Advanced Thermodynamics and Statistical Mechanics
- Solid State Laser Technologies
- Semiconductor Quantum Structures and Devices
Physikalisch-Technische Bundesanstalt
2016-2025
Leibniz University Hannover
2004-2025
Centre National de la Recherche Scientifique
2008
Sorbonne Université
2008
Systèmes de Référence Temps-Espace
2004
Deleted Institution
2004
State University of New York
2000
In this Letter, we present mass-ratio measurements on highly charged <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:msup><a:mrow><a:mi>Yb</a:mi></a:mrow><a:mrow><a:mn>42</a:mn><a:mo>+</a:mo></a:mrow></a:msup></a:mrow></a:math> ions with a precision of <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mn>4</c:mn><c:mo>×</c:mo><c:msup><c:mn>10</c:mn><c:mrow><c:mo>−</c:mo><c:mn>12</c:mn></c:mrow></c:msup></c:math> and isotope-shift...
We present a scalable mixed-species Coulomb crystal clock based on the <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:mrow><a:mrow><a:mmultiscripts><a:mrow><a:msub><a:mrow><a:mi>S</a:mi></a:mrow><a:mrow><a:mn>0</a:mn></a:mrow></a:msub></a:mrow><a:mprescripts/><a:none/><a:mrow><a:mn>1</a:mn></a:mrow></a:mmultiscripts></a:mrow><a:mo...
As relative systematic frequency uncertainties in trapped-ion spectroscopy are approaching the low 10−18 range, motional shifts account for a considerable fraction of uncertainty budget. Micromotion, driven motion fundamentally connected to principle Paul trap, is particular concern these systems. In this article, we experimentally investigate at level three common methods minimizing and determining micromotion amplitude. We develop generalized model quantitative application...
We review experimental progress on optical atomic clocks and frequency transfer, consider the prospects of using these technologies for geodetic measurements. Today, standards have reached relative inaccuracies below 10-17, opening new fields fundamental applied research. The dependence frequencies gravitational potential makes ideal candidates search deviations in predictions Einstein's general relativity, tests modern unifying theories development gravity field sensors. In this review, we...
Ultracold atoms at temperatures close to the recoil limit have been achieved by extending Doppler cooling forbidden transitions. A cloud of ^40Ca has cooled and trapped a temperature as low 6 \mu K operating magneto-optical trap on spin-forbidden intercombination transition. Quenching long-lived excited state with an additional laser enhanced scattering rate factor 15, while high selectivity in velocity was preserved. With this method more than 10% pre-cooled from standard transferred...
Trapped ions are ideally suited for precision spectroscopy, as is evident from the remarkably low systematic uncertainties of single-ion clocks. The major weakness these clocks long averaging time, necessitated by signal a single atom. An increased number can overcome this limitation and allow implementation novel clock schemes. However, presents challenge to maintain excellent control over shifts particle in spatially extended strongly coupled many-body systems. We measure deduce frequency...
With the advent of optical clocks featuring fractional frequency uncertainties on order 10-17 and below, new applications such as chronometric leveling with few-centimeter height resolution emerge. We are developing a transportable clock based single trapped aluminum ion, which is interrogated via quantum logic spectroscopy. employ singly charged calcium ion for sympathetic cooling, state preparation, readout. Here, we present simple compact physics laser package manipulation 40Ca+....
We study the influence of off-resonant two-photon transitions on high-precision measurements with atom interferometers based stimulated Raman transitions. These resonances induce a light shift resonant condition. The impact this effect is investigated in two highly sensitive experiments using gravimeter and gyroscope-accelerometer. show that it can lead to significant systematic phase shifts, which have be taken into account order achieve best performances terms accuracy stability.
In many of the high-precision optical frequency standards with trapped atoms or ions that are under development to date, ac Stark shift induced by thermal radiation leads a major contribution systematic uncertainty. We present an analysis inhomogeneous environment experienced in various types ion traps. Finite element models which allow determination temperature trap structure and were developed for five designs, including operational traps at PTB NPL further optimized designs. Models...
Friction in ordered atomistic layers plays a central role various nanoscale systems ranging from nanomachines to biological systems. It governs transport properties, wear and dissipation. Defects incommensurate lattice constants dramatically change these properties. Recently experimental have become accessible probe the dynamics of nanofriction. Here, we present model system consisting laser-cooled ions which nanofriction processes self-organized with back action can be studied atomic...
Abstract In attempts to unify the four known fundamental forces in a single quantum-consistent theory, it is suggested that Lorentz symmetry may be broken at Planck scale. Here we search for violation low-energy limit by comparing orthogonally oriented atomic orbitals Michelson-Morley-type experiment. We apply robust radiofrequency composite pulse sequence 2 F 7/2 manifold of an Yb + ion, extending coherence time from 200 μ s more than 1 s. this manner, fully exploit high intrinsic...
Optical clocks based on trapped ions can achieve systematic frequency uncertainties below 10${}^{\ensuremath{-}18}$, enabling relativistic geodesy and precise tests of fundamental physics. However, today's single-ion require averaging times over a week to resolve frequencies at this level, no multi-ion clock has been implemented, due difficulties in controlling ion motion. The authors present an ion-trap array that confines up 100 with time-dilation shifts the low-10${}^{\ensuremath{-}19}$...
We report on a transportable and easy-to-operate optical clock utilizing the 2S1/2 - 2D3/2 transition of single trapped 171Yb+ ion at 436 nm. Developed within pilot project for quantum technology in Germany lead by industry, is set up two 19″ racks. In this way, transportation can easily be realized, large degree automatization allows operation outside highly specialized laboratories applications beyond basic research. Comparisons to existing high-accuracy systems enable verification clock's...
We derive a Hamiltonian for the external and internal dynamics of an electromagnetically bound, charged two-particle system in electromagnetic gravitational fields, including leading-order relativistic corrections. apply this to describe coupling cold ions Paul traps, effects micromotion, excess trap imperfections. This provides systematic fully quantum-mechanical treatment frequency shifts atomic clocks based on single trapped ions. Our approach reproduces well-known formulas second-order...
We report on an evaluation of optical clock that uses the ^{2}S_{1/2}→^{2}D_{5/2} transition a single ^{88}Sr^{+} ion as reference. In contrast to previous work, we estimate effective temperature blackbody radiation shifts reference directly during operation from corresponding frequency shift and well-characterized sensitivity thermal radiation. measure output against independent ^{171}Yb^{+} clock, based ^{2}S_{1/2}(F=0)→^{2}F_{7/2}(F=3) electric octupole (E3) transition, determine ratio...
We develop a concept of atomic clocks where the blackbody radiation shift and its fluctuations can be suppressed by 1--3 orders magnitude independent environmental temperature. The suppression is based on fact that in system with two accessible clock transitions (with frequencies ${\ensuremath{\nu}}_{1}$ ${\ensuremath{\nu}}_{2}$) which are exposed to same thermal environment, there exists ``synthetic'' frequency ${\ensuremath{\nu}}_{\mathrm{syn}}$ $\ensuremath{\propto}$...
We study experimentally and theoretically the properties of structural defects (kink solitons) in two-dimensional ion Coulomb crystals. show how different types kink solitons with physical can be realized, transformed from one type into another by varying aspect ratio trap confinement. Further, we discuss impurities crystals, such as mass defects, modify dynamics creation their stability. For both pure impure observed are analysed detail explained numerical simulations calculations...
Abstract Photoexcitation of trapped ions by Hermite–Gaussian (HG) modes from guided beam structures is proposed and investigated theoretically. In particular, simple analytical expressions for the matrix elements induced atomic transitions are derived that depend both on parameters HG beams geometry an experiment. By using these general expressions, electric octupole (E3) transition in Yb + ion, localized low–intensity center 10 01 beams. It shown how corresponding Rabi frequency can be...
We have developed a universal method to form the reference signal for stabilization of arbitrary atomic clocks based on Ramsey spectroscopy. Our approach uses an interrogation scheme system with two different periods and specially constructed combined error (CES) computed by subtracting signals appropriate calibration factor. CES spectroscopy allows perfect elimination probe-induced light shifts does not suffer from effects relaxation, time-dependent pulse fluctuations phase-jump modulation...