entanglement; Bose-Einstein condensation; quantum metrology; quantum state tomography; phase coherence; atom chips; ultracold atoms
Schmied Roman, Bancal Jean-Daniel, Allard Baptiste, Fadel Matteo, Scarani Valerio, Treutlein Philipp, Sangouard Nicolas (2016), Bell correlations in a Bose-Einstein condensate, in Science
, 352, 441.
Horsley Andrew, Treutlein Philipp (2016), Frequency-tunable microwave field detection in an atomic vapor cell, in Applied Physics Letters
, 108, 211102.
Schmied Roman (2016), Quantum state tomography of a single qubit: comparison of methods, in Journal of Modern Optics
, 63, 1744.
Allard Baptiste, Fadel Matteo, Schmied Roman, Treutlein Philipp (2016), Sideband Rabi spectroscopy of finite-temperature trapped Bose gases, in Physical Review A
, 93, 043624.
Affolderbach Christoph, Du Guan-Xiang, Bandi Thejesh, Horsley Andrew, Treutlein Philipp, Mileti Gaetano (2015), Imaging Microwave and DC Magnetic Fields in a Vapor-Cell Rb Atomic Clock, in IEEE Transactions on Instrumentation and Measurement
, 64(12), 3629-3629.
Horsley Andrew, Du Guan-Xiang, Treutlein Philipp (2015), Widefield microwave imaging in alkali vapor cells with sub-100 $μ$m resolution, in New Journal of Physics
, 17, 112002.
Entanglement is one of the most fascinating and at the same time puzzling concepts of physics. Besides being of fundamental interest, it is at the heart of quantum technologies such as quantum information processing and quantum metrology, which are expected to have a strong impact on our future way of computing and measuring. While entanglement of two particles is a relatively well-studied concept, entanglement in many-body systems is much less understood. Many different classes of entangled states exist and it is important to investigate which classes offer advantages in performing a given technological task, such as a high-precision measurement. In this project, we use small atomic Bose-Einstein condensates on an atom chip - an exceptionally well-controlled quantum many-body system - to perform fundamental studies of many-particle entangled states and to explore their usefulness for quantum technology. Moreover, we will investigate the fundamental limits of phase coherence in atomic Bose-Einstein condensates and study the implications of these limits. The concepts and technologies investigated in this project are relevant for compact atomic clocks and atom interferometers measuring electromagnetic fields, gravity, and other fundamental quantities.