255 citations · 847 across the 11 of their papers we have counts for
11 papers
Scalable creation of long-lived multipartite entanglement
H. Kaufmann, T. Ruster, C. T. Schmiegelow +6
We demonstrate the deterministic generation of multipartite entanglement based on scalable methods. Four qubits are encoded in Ca, stored in a micro-structured segmented…
Entanglement-based dc magnetometry with separated ions
T. Ruster, H. Kaufmann, M. A. Luda +4
We demonstrate sensing of inhomogeneous dc magnetic fields by employing entangled trapped ions, which are shuttled in a segmented Paul trap. As \textit{sensor states}, we use Bell…
Cryogenic setup for trapped ion quantum computing
M. F. Brandl, M. W. van Mourik, L. Postler +15
We report on the design of a cryogenic setup for trapped ion quantum computing containing a segmented surface electrode trap. The heat shield of our cryostat is designed to attenua…
Fast ion swapping for quantum information processing
Henning Kaufmann, Thomas Ruster, Christian T. Schmiegelow +6
We demonstrate a SWAP gate between laser-cooled ions in a segmented microtrap via fast physical swapping of the ion positions. This operation is used in conjunction with qubit init…
A long-lived Zeeman trapped-ion qubit
Thomas Ruster, Christian T. Schmiegelow, Henning Kaufmann +3
We demonstrate a coherence time of 2.1(1)~s for electron spin superposition states of a single trapped Ca ion. The coherence time, measured with a spin-echo experiment,…
Excitation of an Atomic Transition with a Vortex Laser Beam
Christian T. Schmiegelow, Jonas Schulz, Henning Kaufmann +3
Photons carry one unit of angular momentum associated with their spin~\cite{Beth1936}. Structured vortex beams carry additional orbital angular momentum which can also be transferr…
Measurement of dipole matrix elements with a single trapped ion
M. Hettrich, T. Ruster, H. Kaufmann +4
We demonstrate a new method for the direct measurement of atomic dipole transition matrix elements based on techniques developed for quantum information purposes. The scheme consis…
Experimental realization of fast ion separation in segmented Paul traps
Thomas Ruster, Claudia Warschburger, Henning Kaufmann +7
We experimentally demonstrate fast separation of a two-ion crystal in a microstructured segmented Paul trap. By the use of spectroscopic calibration routines for the electrostatic…
Dynamics and control of fast ion crystal splitting in segmented Paul traps
H. Kaufmann, T. Ruster, C. T. Schmiegelow +2
We theoretically investigate the process of splitting two-ion crystals in segmented Paul traps, i.e. the structural transition from two ions confined in a common well to ions confi…
Experimental creation and analysis of displaced number states
F. Ziesel, T. Ruster, A. Walther +4
We create displaced number states, which are nonclassical generalizations of coherent states, of a vibrational mode of a single trapped ion.
Controlling fast transport of cold trapped ions
Andreas Walther, Frank Ziesel, Thomas Ruster +6
We realize fast transport of ions in a segmented micro-structured Paul trap. The ion is shuttled over a distance of more than 10^4 times its groundstate wavefunction size during on…