Realization of a Decoherence-free, Optimally Distinguishable Mesoscopic Quantum Superposition

Realization of an optimally distinguishable multiphoton quantum superposition.

We report the realization of an entangled quantum superposition of M approximately 12 photons by multiple universal cloning of a single-photon qubit via the high gain, quantum-injected optical parametric amplification. The system has been found extremely resilient to decoherence. By quantum tomography, the nonseparability and the quantum superposition are demonstrated for the mesoscopic output ...

Realization of a Classically Distinguishable Multi-photon Quantum Superposition

We report the successful generation of an entangled multiparticle quantum superposition of pure photon states. They result from a multiple universal cloning of a single photon qubit by a high gain, quantum-injected parametric amplifier. The information preserving property of the process suggests for these states the name of ”multi-particle qubits”. They are ideal objects for investigating the e...

Mesoscopic quantum superpositions in bimodal Bose-Einstein condensates: decoherence and strategies to counteract it

Reversible Decoherence of a Mesoscopic Superposition of Field States

We describe the blueprint of an experiment in which the decoherence of a mesoscopic superposition of radiation states (“Schrödinger cat”) becomes a reversible process. When the high Q cavity containing the Schrödinger cat is coupled to another resonator, the mesoscopic quantum coherence first decays rapidly, then exhibits sharp revivals with the period of the energy exchange between the two cav...

Macroscopic Coherence for a Trapped Electron

One of the fundamental aspects of quantum mechanics is the exsistence of interfertence among quantum states which signs the difference between a superposition of states and a mixture of states. However, as soon as the superposition principle is extended to the macroscopic world the Schrödinger’s cat paradoxe [1] arises. Practically the visibility of such curious superposition states at macrosco...