TY  - GEN
ID  - heidok23769
UR  - https://archiv.ub.uni-heidelberg.de/volltextserver/23769/
Y1  - 2017///
AV  - public
TI  - Control and characterisation of a Rydberg spin system to explore many-body physics
A1  - Ferreira Cao, Miguel
N2  - This thesis explores the implementation of a spin-1/2 system to realise quantum simulation of Heisenberg XX and XXZ models. The spins are mapped onto two high-lying atomic levels, so-called Rydberg states, in an ultracold sample of 87Rb and coupled by a microwave field. Efficient synthesis and control of the driving field has been introduced in the setup in order to probe the spin dynamics with NMR sequences. Two- and three-photon excitation schemes are implemented to prepare the Rydberg spins. In order to spatially resolve the Rydberg excitation dynamics, a new imaging technique is employed, which uses the depletion of absorption in presence of Rydberg atoms to detect their distribution in the atomic cloud, revealing the emergence of spatial order of the Rydberg excitations due to strong van der Waals interactions. To benchmark the validity of this platform, the coherence of the spin ensemble is measured by Ramsey techniques in the low-density regime, where the single-spin dynamics accurately describes the observations. Despite the black-body redistribution of Rydberg spins setting a limit for the T2* time of the spin system, the coherence is measured to persist over long timescales on the order of 130 ?s. Thus, scaling up the density of spins, first signatures of dipolar many-body effects for |nS? ? |nP? (XX) and |nS? ? |(n + 1)S? (XXZ) spin combinations have been observed.
KW  - Rydberg atoms
KW  -  spin dynamics
KW  -  microwave control
KW  -  atomic spectroscopy
KW  -  quantum control
KW  -  many-body physics
KW  -  quantum magnetism
KW  -  Heisenberg model
KW  -  imaging
KW  -  absorption imaging
KW  -  interaction enhanced imaging.
ER  -