Publications (10)
Realization of Universal Ion Trap Quantum Computation with Decoherence Free Qubits
T. Monz, K. Kim, A. S. Villar +8
Any residual coupling of a quantum computer to the environment results in computational errors. Encoding quantum information in a so-called decoherence-free subspace provides means…
Scalable multi-particle entanglement of trapped ions
H. Haeffner, W. Haensel, C. F. Roos +11
Among the various kinds of entangled states, the 'W state' plays an important role as its entanglement is maximally persistent and robust even under particle loss. Such states are…
Precision spectroscopy with two correlated atoms
M. Chwalla, K. Kim, T. Monz +4
We discuss techniques that allow for long coherence times in laser spectroscopy experiments with two trapped ions. We show that for this purpose not only entangled ions prepared in…
Realization of the quantum Toffoli gate with trapped ions
T. Monz, K. Kim, W. Hänsel +6
Algorithms for quantum information processing are usually decomposed into sequences of quantum gate operations, most often realized with single- and two- qubit gates[1]. While such…
Robust entanglement
H. Haeffner, F. Schmidt-Kaler, W. Haensel +8
It is common belief among physicists that entangled states of quantum systems loose their coherence rather quickly. The reason is that any interaction with the environment which di…
Experimental multiparticle entanglement dynamics induced by decoherence
J. T. Barreiro, P. Schindler, O. Gühne +5
Multiparticle entanglement leads to richer correlations than two-particle entanglement and gives rise to striking contradictions with local realism, inequivalent classes of entangl…
'Designer atoms' for quantum metrology
C. F. Roos, M. Chwalla, K. Kim +2
Entanglement is recognized as a key resource for quantum computation and quantum cryptography. For quantum metrology, the use of entangled states has been discussed and demonstrate…
Quantum teleportation with atoms: quantum process tomography
M. Riebe, M. Chwalla, J. Benhelm +4
The performance of a quantum teleportation algorithm implemented on an ion trap quantum computer is investigated. First the algorithm is analyzed in terms of the teleportation fide…
STE-QUEST - Test of the Universality of Free Fall Using Cold Atom Interferometry
D. Aguilera, H. Ahlers, B. Battelier +63
The theory of general relativity describes macroscopic phenomena driven by the influence of gravity while quantum mechanics brilliantly accounts for microscopic effects. Despite th…
Absolute frequency measurement of the 40Ca+ S1/2 - D5/2 clock transition
M. Chwalla, J. Benhelm, K. Kim +12
We report on the first absolute transition frequency measurement at the 10^{-15} level with a single, laser-cooled 40Ca+ ion in a linear Paul trap. For this measurement, a frequenc…