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Quantum metrology with nonclassical states of atomic ensembles
Quantum technologies exploit entanglement to revolutionize computing, measurements, and communications. This has stimulated the research in different areas of physics to engineer and manipulate
Direct observation of tunneling and nonlinear self-trapping in a single bosonic Josephson junction.
A novel nonlinear effect known as macroscopic quantum self-trapping, which leads to the inhibition of large amplitude tunneling oscillations in superconducting and superfluid Josephson junctions is confirmed.
Dynamics of Bose-Einstein condensates in optical lattices
Matter waves inside periodic potentials are well known from solid-state physics, where electrons interacting with a crystal lattice are considered. Atomic Bose-Einstein condensates inside
Nonlinear atom interferometer surpasses classical precision limit
It is shown experimentally that the classical precision limit can be surpassed using nonlinear atom interferometry with a Bose–Einstein condensate and the results provide information on the many-particle quantum state, and imply the entanglement of 170 atoms.
Feynman path-integral treatment of the BEC-impurity polaron
The description of an impurity atom in a Bose-Einstein condensate can be cast in the form of Frohlich's polaron Hamiltonian, where the Bogoliubov excitations play the role of the phonons. An
Experimental observation of oscillating and interacting matter wave dark solitons.
An effective particle picture is developed and confirms that the deviation of the observed oscillation frequencies from the asymptotic prediction nu(z)/sqrt 2, where nu( z) is the longitudinal trapping frequency, results from the dimensionality of the system and the soliton interactions.
Fisher information and entanglement of non-Gaussian spin states
A general method is developed to extract the Fisher information, which reveals that the quantum dynamics of a classically unstable system creates quantum states that are not spin squeezed but nevertheless entangled, which quantifies metrologically useful entanglement.
Squeezing and entanglement in a Bose–Einstein condensate
Spin squeezed states suitable for atomic interferometry are demonstrated by splitting a condensate into a few parts using a lattice potential by implying entanglement between the particles.
A bosonic Josephson junction
We review the experimental realization of a single bosonic Josephson junction for ultracold gases, which was made possible by the generation of a precisely controllable double-well potential for