ultracold atoms; atom chips; entanglement; quantum metrology; quantum information processing; Bose-Einstein condensation; quantum coherence; atomic clock; quantum computing; quantum simulation; spin-squeezing
Horsley Andrew, Du Guan-Xiang, Pellaton Matthieu, Affolderbach Christoph, Mileti Gaetano, Treutlein Philipp (2013), Imaging of Relaxation Times and Microwave Field Strength in a Microfabricated Vapor Cell, in Phys. Rev. A
, 88, 063407.
Ockeloen Caspar F., Schmied Roman, Riedel Max F., Treutlein Philipp (2013), Quantum Metrology with a Scanning Probe Atom Interferometer, in Phys. Rev. Lett.
, 111, 143001-143001.
Kurkjian Hadrien, Pawłowski Krzysztof, Sinatra Alice, Treutlein Philipp (2013), Spin squeezing and Einstein-Podolsky-Rosen entanglement of two bimodal condensates in state-dependent potentials, in Phys. Rev. A
, 88(4), 043605-043605.
Böhi Pascal, Treutlein Philipp (2012), Simple microwave field imaging technique using hot atomic vapor cells, in Appl. Phys. Lett.
, 101, 181107-181107-4.
Folman Ron, Treutlein Philipp, Schmiedmayer Jörg (2011), Atom Chip Fabrication, in Reichel Jakob and Vuletic Vladan (ed.), Wiley-VCH, Weinheim, Germany, 61-117.
Böhi Pascal, Riedel Max F., Treutlein Philipp (2011), Cold atoms image microwave fields, in SPS Communications
, 33, 10-12.
Negretti Antonio, Treutlein Philipp, Calarco Tommaso (2011), Quantum computing implementations with neutral particles, in Quantum Information Processing
, 10, 721-753.
Treutlein Philipp, Negretti Antonio, Calarco Tommaso (2011), Quantum Information Processing with Atom Chips, in Reichel Jakob and Vuletic Vladan (ed.), Wiley-VCH, Weinheim, Germany, 283-308.
Schmied Roman, Treutlein Philipp (2011), Tomographic reconstruction of the Wigner function on the Bloch sphere, in New Journal of Physics
, 13, 065019-18pp.
Entanglement-based technologies, such as quantum information processing, quantum simulations, and quantum metrology, have the potential to revolutionize our way of computing and measuring, and help to clarify the puzzling concept of entanglement itself. Ultracold atoms on atom chips are an attractive system for their implementation, as they provide control over quantum systems in compact, robust, and scalable setups. This proposal consists of three projects investigating entanglement on atom chips, focusing on both fundamental physics and possible applications: The study of multi-particle entanglement for quantum metrology, the development of novel techniques for chip-based quantum state control, and the realization of a two-qubit quantum gate.Research on multi-particle entanglement for quantum metrology (project A) currently receives great interest. Such entanglement, e.g. in the form of spin-squeezed states, provides a way to overcome the standard quantum limit of interferometric measurement, which is reached in today's best atomic clocks. We propose to study multi-particle entanglement in an ensemble of ultracold atoms, using a technique that is entirely chip-based and relies on collisions in a state-dependent potential. We will thoroughly study this technique and explore its usefulness for chip-based atomic clocks operating beyond the standard quantum limit. The nature of entanglement between indistinguishable particles, such as the atoms in a Bose-Einstein condensate, is much less understood than entanglement between individually addressable particles. We propose to study measures of entanglement which allow to better identify and quantify such entanglement and understand its relation to indistinguishability. Sophisticated techniques for quantum state control on atom chips (project B) are essential for the generation and manipulation of entanglement. We propose to further develop such techniques based on microwave near-fields on atom chips. We intend to perform a full characterization of microwave near-field potentials, to use microwave near-fields for coherent manipulation of vibrational qubits, and to develop techniques for the addressing and independent coherent manipulation of multiple ensembles of atoms on the same chip. The demonstration of a fundamental two-qubit quantum gate (project C) is an important milestone on the way to atom chip based quantum computing. In a first step, we propose to entangle two small ensembles of ultracold atoms using the techniques developed in project B. In a second step, which will be carried out in collaboration with the group of Prof. Jakob Reichel in Paris, we intend to realize a quantum gate between two individual atoms on an atom chip. The main applicant, Prof. Dr. Philipp Treutlein, is a young assistant professor in the Department of Physics at the University of Basel. He is currently designing a new ultracold atom laboratory, which will be completed in fall 2010. He has 10 years of experience in ultracold atom experiments, obtained in some of the world-leading laboratories at Stanford, Konstanz, and Munich. His expertise in atom chips comes from 7 years at MPQ and LMU Munich, where he was first a doctoral student with Dr. Jakob Reichel and Prof. Theodor W. Hänsch and later became the leader of the atom chip experiments. In Basel, we propose to set up an experiment that is unique in Switzerland, and with our Swiss and international collaborators we form a competitive team to investigate entanglement for chip-based quantum technologies.