{"id":{"repo_id":"freiburg-diss","oai_identifier":"oai:freidok.uni-freiburg.de:1664"},"canonical_url":"https://search.dev.ndltd.org/etd/freiburg-diss/oai:freidok.uni-freiburg.de:1664","repository":{"repo_id":"freiburg-diss","name":"University of Freiburg","base_url":"https://freidok.uni-freiburg.de/oai/oai2.php"},"display":{"title":"Interactions in an ultracold gas of Rydberg atoms","abstract":"This thesis presents observations of ultralong range interactions
in a frozen Rydberg gas. The observed signatures are interactioninduced
line broadenings and a suppression of resonant Rydberg excitation.
The latter effect can be interpreted as the onset of a local dipole
blockade and can be exploited to perform quantum information processing
with mesoscopic ensembles. The dominating interaction between a
pair of Rydberg atoms separated as far as 100 000 Bohr radii is the
van der Waals interaction. The strength of this interaction is calculated
quantitatively in a perturbative approach. We describe in detail our
experimental apparatus which employs narrow-bandwidth continuouswave
(cw) laser excitation in a two-photon excitation process to produce
a frozen Rydberg gas from magneto-optically trapped 87Rb atoms. As a
particular feature of the apparatus we have implemented a novel scheme
for the coherent addition of laser intensities and we have realized 3D degenerate
Raman sideband cooling resulting in atom cloud temperatures
in the sub-µK range. Systematic studies of the Rydberg spectra as
a function of excitation-laser intensity, density of excitable atoms and
excitation time are presented.","abstract_html":"This thesis presents observations of ultralong range interactions <br>in a frozen Rydberg gas. The observed signatures are interactioninduced <br>line broadenings and a suppression of resonant Rydberg excitation. <br>The latter effect can be interpreted as the onset of a local dipole <br>blockade and can be exploited to perform quantum information processing <br>with mesoscopic ensembles. The dominating interaction between a <br>pair of Rydberg atoms separated as far as 100 000 Bohr radii is the <br>van der Waals interaction. The strength of this interaction is calculated <br>quantitatively in a perturbative approach. We describe in detail our <br>experimental apparatus which employs narrow-bandwidth continuouswave <br>(cw) laser excitation in a two-photon excitation process to produce <br>a frozen Rydberg gas from magneto-optically trapped 87Rb atoms. As a <br>particular feature of the apparatus we have implemented a novel scheme <br>for the coherent addition of laser intensities and we have realized 3D degenerate <br>Raman sideband cooling resulting in atom cloud temperatures <br>in the sub-µK range. Systematic studies of the Rydberg spectra as <br>a function of excitation-laser intensity, density of excitable atoms and <br>excitation time are presented.","abstract_has_math":false,"creators":["Singer, Kilian Talo Theodor"],"institution":null,"degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":["Weidemüller, Matthias"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":null,"date_issued":"","date_published":null,"updated_at":"2026-07-24T02:22:22Z","subjects":["Wechselwirkung, ultrakalte Gase","Rydberg atoms, interaction, ultracold gases"],"languages":[],"rights":[],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://freidok.uni-freiburg.de/data/1664","outbound_label":"Repository record","outbound_source":"source_url"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Weidemüller, Matthias"]},{"key":"dc:creator","label":"Author","values":["Singer, Kilian Talo Theodor"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:type","label":"Dc Type","values":["DoctoralThesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Wechselwirkung, ultrakalte Gase","Rydberg atoms, interaction, ultracold gases"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This thesis presents observations of ultralong range interactions
in a frozen Rydberg gas. The observed signatures are interactioninduced
line broadenings and a suppression of resonant Rydberg excitation.
The latter effect can be interpreted as the onset of a local dipole
blockade and can be exploited to perform quantum information processing
with mesoscopic ensembles. The dominating interaction between a
pair of Rydberg atoms separated as far as 100 000 Bohr radii is the
van der Waals interaction. The strength of this interaction is calculated
quantitatively in a perturbative approach. We describe in detail our
experimental apparatus which employs narrow-bandwidth continuouswave
(cw) laser excitation in a two-photon excitation process to produce
a frozen Rydberg gas from magneto-optically trapped 87Rb atoms. As a
particular feature of the apparatus we have implemented a novel scheme
for the coherent addition of laser intensities and we have realized 3D degenerate
Raman sideband cooling resulting in atom cloud temperatures
in the sub-µK range. Systematic studies of the Rydberg spectra as
a function of excitation-laser intensity, density of excitable atoms and
excitation time are presented.","In dieser Doktorarbeit werden die langreichweitigen Wechselwirkungen
in einem ultrakalten Gas aus Rydbergatomen untersucht.
Die beobachteten Signaturen sind wechselwirkungsverursachte
Linienverbreiterungen und eine Anregungsunterdrückung bei resonanter
Rydberganregung. Der letztere Effekt kann als Beginn einer lokalen
Dipolblockade interpretiert werden, welche zur Realisierung von Quanteninformationsverarbeitung mit mesoskopischen Gesamtheiten ausgenutzt
werden kann. Die dominierende Wechselwirkung zwischen zwei
Rydbergatomen in einem Abstand von 100 000 Bohrradien ist die
van-der-Waals-Wechselwirkung. Die Stärke der Wechselwirkung wurde
quantitativ in einem st¨orungstheoretischen Ansatz berechnet. Der experimentelle
Aufbau wird detailliert beschrieben. Wir setzen schmalbandige
kontinuierliche Laseranregung in einem Zweiphotonenprozess
zur Rydberganregung aus magneto-optisch gefangenen 87Rb Atomen
ein. In unserem Aufbau kommt ein neuartiges Verfahren zur kohärenten
Addition von Laserintensitäten zum Einsatz. Des Weiteren wurde 3D
entartete Ramanseitenbandkühlung implementiert und Atomwolkentemperaturen
im unteren µK Bereich erreicht. Systematische Studien
der Rydbergspektren als Funktion der Anregungslaserintensitäten, der
Dichte der anregbaren Atomen und der Anregungszeit wurden durchgeführt."]},{"key":"dc:format.medium","label":"Dc Format Medium","values":["application/pdf"]},{"key":"dc:title","label":"Title","values":["Interactions in an ultracold gas of Rydberg atoms","Wechselwirkungen in einem ultrakalten Gas aus Rydbergatomen"]}]}],"canonical_facts":{"dc:contributor":["Weidemüller, Matthias"],"dc:creator":["Singer, Kilian Talo Theodor"],"dc:description.abstract":["This thesis presents observations of ultralong range interactions
in a frozen Rydberg gas. The observed signatures are interactioninduced
line broadenings and a suppression of resonant Rydberg excitation.
The latter effect can be interpreted as the onset of a local dipole
blockade and can be exploited to perform quantum information processing
with mesoscopic ensembles. The dominating interaction between a
pair of Rydberg atoms separated as far as 100 000 Bohr radii is the
van der Waals interaction. The strength of this interaction is calculated
quantitatively in a perturbative approach. We describe in detail our
experimental apparatus which employs narrow-bandwidth continuouswave
(cw) laser excitation in a two-photon excitation process to produce
a frozen Rydberg gas from magneto-optically trapped 87Rb atoms. As a
particular feature of the apparatus we have implemented a novel scheme
for the coherent addition of laser intensities and we have realized 3D degenerate
Raman sideband cooling resulting in atom cloud temperatures
in the sub-µK range. Systematic studies of the Rydberg spectra as
a function of excitation-laser intensity, density of excitable atoms and
excitation time are presented.","In dieser Doktorarbeit werden die langreichweitigen Wechselwirkungen
in einem ultrakalten Gas aus Rydbergatomen untersucht.
Die beobachteten Signaturen sind wechselwirkungsverursachte
Linienverbreiterungen und eine Anregungsunterdrückung bei resonanter
Rydberganregung. Der letztere Effekt kann als Beginn einer lokalen
Dipolblockade interpretiert werden, welche zur Realisierung von Quanteninformationsverarbeitung mit mesoskopischen Gesamtheiten ausgenutzt
werden kann. Die dominierende Wechselwirkung zwischen zwei
Rydbergatomen in einem Abstand von 100 000 Bohrradien ist die
van-der-Waals-Wechselwirkung. Die Stärke der Wechselwirkung wurde
quantitativ in einem st¨orungstheoretischen Ansatz berechnet. Der experimentelle
Aufbau wird detailliert beschrieben. Wir setzen schmalbandige
kontinuierliche Laseranregung in einem Zweiphotonenprozess
zur Rydberganregung aus magneto-optisch gefangenen 87Rb Atomen
ein. In unserem Aufbau kommt ein neuartiges Verfahren zur kohärenten
Addition von Laserintensitäten zum Einsatz. Des Weiteren wurde 3D
entartete Ramanseitenbandkühlung implementiert und Atomwolkentemperaturen
im unteren µK Bereich erreicht. Systematische Studien
der Rydbergspektren als Funktion der Anregungslaserintensitäten, der
Dichte der anregbaren Atomen und der Anregungszeit wurden durchgeführt."],"dc:format.medium":["application/pdf"],"dc:subject":["Wechselwirkung, ultrakalte Gase","Rydberg atoms, interaction, ultracold gases"],"dc:title":["Interactions in an ultracold gas of Rydberg atoms","Wechselwirkungen in einem ultrakalten Gas aus Rydbergatomen"],"dc:type":["DoctoralThesis"]},"updated_at":"2026-07-24T02:22:22Z"}