Quantum optics experiments in a microstructured ion trap [Elektronische Ressource] / vorgelegt von Ulrich Georg Poschinger

Sujets

• Physik

Informations

• Publié par: universitat_ulm
• Publié le: 01 janvier 2010
• Nombre de lectures: 11
• Langue: English
• Poids de l'ouvrage: 11 Mo

Extrait

Quantum Optics Experiments in a
Microstructured Ion Trap
Dissertation
zur Erlangung des Doktorgrades Dr. rer. nat.
der Fakult¨at fur¨ Naturwissenschaften der Universit¨at Ulm
vorgelegt von
Ulrich Georg Poschinger
aus Berlin
2010Amtierender Dekan: Prof. Dr. Axel Groß
Erstgutachter: Prof. Dr. Ferdinand Schmidt-Kaler
Zweitgutachter: Prof. Dr. Johannes Hecker Denschlag
Tag der mündlichen Prüfung: 15.2.2011
Hiermit erklare¨ ich, Ulrich Poschinger, dass ich die vorliegende Dissertation Quantum
Optics Experiments in a Microstructured Ion Trap selbststandig¨ angefertigt und keine an-
deren als die angegebenen Quellen und Hilfsmittel benutzt sowie die wo¨rtlich und inhaltlich
u¨bernommenen Stellen als solche kenntlich gemacht und die Satzung der Universitat¨ Ulmzur
Sicherung guter wissenschaftlicher Praxis beachtet habe.
Ulrich
Poschinger
Ulm, den 12. November 2010
The work described in this thesis was carried out at the
Universitat¨ Ulm
Institut fur¨ Quanteninformationsverarbeitung
Albert-Einstein-Allee 11
D-89069 Ulm
Funding from the EU within the research programs
MICROTRAP, SCALA, AQUTE and the MRTN EMALI,
and from the DFG within the framework SFB/TRR21
is gratefully acknowledged.Extraordinary rains pretty generally fall after great battles.
-PlutarchAbstract
This dissertation describes a prototype experiment aiming at the realization of scalable quan-
tum information. The essential feature is the usage of a novel microstructured ion trap de-
rived from the Paul trap. It allows for storing and manipulating a large number of ions,
as compared to conventional linear Paul traps. This thesis describes how the way is paved
towards the realization of quantum information experiments in this ion trap. An analysis
of the electrostatic properties of the ion trap is presented, which is laying the foundation
for understanding the limits of confinement stability and effects beyond standard Paul trap
behavior. The focus of this work lies on the realization and characterization of single and
dual qubit operations, which are achieved by means of (semiclassical) atom-light interaction.
In our experiment, the qubit is implemented in the Zeeman sublevels of the ion’s ground
40 +state, i.e. in the spin of the bright electron of a Ca ion. The main body of this the-
sis then describes the realization of the necessary steps of preparation, manipulation and
readout of this qubit. The preparation includes optical pumping and cooling close to the
motional quantum ground state by means of sideband cooling. Several possible techniques
for these steps are tested and analyzed. Coherent manipulations are carried out by means
of stimulated Raman transitions. Here, a strong emphasis is put on the characterization of
the various decoherence mechanisms, which are dominated by the motional excitation of the
ion due to thermalization of the ion with the trap electrodes, and by imperfections in the
ion-laser interactions. As by-product of the latter investigation, a new measurement scheme
for the experimental determination of atomic dipole matrix elements is presented. Finally,
experimental results on the preparation of Schr¨odinger Cat states and on the tomography of
a single ion’s motional state are presented. It is also described how Schr¨odinger Cat states
can be used as a measurement tool for the ultraprecise monitoring of a single ion’s phase
space trajectory, where deviations from the Lamb-Dicke limit dynamics are seen.
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