Dr. Christof Wunderlich and Prof. Dr. Werner Neuhauser
The Hamburg group has long standing experience in manipulating trapped ions: Previous related work includes, for example, the first demonstration of continuous excitation of resonance fluorescence of trapped ions, the first observation of laser cooling (at the same time and independently from other researchers), and the first recording of the excitation spectrum of a single atom.
Examples of recent work include the study of the collective vibrational motion of two trapped 138Ba+ ions cooled by laser light. Parameter regimes of the laser light irradiating the ions are identified that imply most efficient laser cooling and are least susceptible to drifts, fluctuations, and uncertainties in laser parameters.
Determining an arbitrary state of a quantum system is a task of central importance in quantum physics, and in particular in quantum information processing and communication. Optimal strategies to read out information encoded in the quantum state of a given number N of identical qubits require intricate measurements using a basis of entangled states. We have performed a self-learning estimation of arbitrary single qubits, represented by the ground state hyperfine levels of electrodynamically trapped 171Yb+. The base of measurement is varied during a sequence of N measurements conditioned on the results of previous measurements in a sequence.
A scheme for QIP with ion traps has been developed that combines the best features of two "worlds": qubits in ion traps can be individually addressed and are well isolated from the environment thus exhibiting long coherence times, however major obstacles still are in our way to exploiting these features for QIP. On the other hand, for NMR experiments all the necessary tools have been developed over decades. It was shown how qubits in ion traps can be manipulated using microwave radiation thus taking advantage of NMR techniques and circumventing major experimental stumbling stones.
Back to Research
Back to Participants