How to observe a coherent superposition of an atom and a molecule
arXiv:quant-ph/0606128 · doi:10.1103/PhysRevA.74.052113
Abstract
We demonstrate that it is possible, in principle, to perform a Ramsey-type interference experiment to exhibit a coherent superposition of a single atom and a diatomic molecule. This gedanken experiment, based on the techniques of Aharonov and Susskind [Phys. Rev. 155, 1428 (1967)], explicitly violates the commonly-accepted superselection rule that forbids coherent superpositions of eigenstates of differing atom number. This interference experiment makes use of a Bose-Einstein condensate as a reference frame with which to perform the coherent operations analogous to Ramsey pulses. We also investigate an analogous gedanken experiment to exhibit a coherent superposition of a single boson and a fermion, violating the commonly-accepted superselection rule forbidding coherent superpositions of states of differing particle statistics; in this case, the reference frame is realized by a multi-mode state of many fermions. This latter case reproduces all of the relevant features of Ramsey interferometry, including Ramsey fringes over many repetitions of the experiment. However, the apparent inability of this proposed experiment to produce well-defined relative phases between two distinct systems each described by a coherent superposition of a boson and a fermion demonstrates that there are additional, outstanding requirements to fully ``lift'' the univalence superselection rule.
17 pages, 1 figure, comments welcome, published version (minor changes)
References in corpus (30)
- Theory of Bose-Einstein condensation in trapped gases
- Coherent control of macroscopic quantum states in a single-Cooper-pair box
- Fermionic quantum computation
- Creation of ultracold molecules from a Fermi gas of atoms
- Fermionic atoms in a 3D optical lattice: Observing Fermi-surfaces, dynamics and interactions
- Atom--Molecule Coherence in a Bose-Einstein Condensate
- A Quantum Rosetta Stone for Interferometry
- Two-species mixture of quantum degenerate Bose and Fermi gases
- A two atomic species superfluid
- Fermi-Bose quantum degenerate ^40 K - ^87 Rb mixture with attractive interaction
- The entanglement of indistinguishable particles shared between two parties
- Superchemistry: dynamics of coupled atomic and molecular Bose-Einstein condensates
- A particle-number-conserving Bogoliubov method which demonstrates the validity of the time-dependent Gross-Pitaevskii equation for a highly condensed Bose gas
- Postselected versus nonpostselected quantum teleportation using parametric down-conversion
- Density Operators for Fermions
- Continuous Observation of Interference Fringes from Bose Condensates
- Superselection rules and quantum protocols
- Quantum-degenerate mixture of fermionic lithium and bosonic rubidium gases
- Magnetic control of the interaction in ultracold K-Rb mixtures
- Interference of Bose condensates
- Gaussian quantum Monte Carlo methods for fermions
- Quantum nonlocality in the presence of superselection rules and data hiding protocols
- Dialogue Concerning Two Views on Quantum Coherence: Factist and Fictionist
- Photon-number superselection and the entangled coherent-state representation
- Collective molecule formation in a degenerate Fermi gas via a Feshbach resonance
- Superposition of macroscopic numbers of atoms and molecules
- Entanglement under restricted operations: Analogy to mixed-state entanglement
- Measurement Induced Localization of Relative Degrees of Freedom
- Quantum coherence in the presence of unobservable quantities
- Quasiclassical and Statistical Properties of Fermion Systems
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