Research Highlights

Big leap towards quantum computing

doi:10.1038/nindia.2012.14 Published online 31 January 2012

Decoherence — the loss of information from a system to its surrounding environment — is a phenomenon that poses a significant challenge in the development of quantum computers. A new theoretical model now suggests the ability to create vacuum-induced coherence (VIC) at the molecular level by probing laser-trapped ultracold atoms of ytterbium. This research will have potential applications for controlling decoherence, which is a major hindrance in quantum information processing.

A clear signature of VIC in atomic systems has so far eluded researchers. The researchers considered the use of photoassociation spectroscopy to search for signs of VIC in ytterbium atoms cooled to temperatures of 10–100 μK. In their model, photoassociation lasers excite two free atoms of ytterbium to the desired bound states. At large separation distances, the excited bound states correspond to one atom in an excited state and the other in the ground state.

The study demonstrates that it is possible to generate and manipulate coherence between two excited states of a molecule. The ytterbium atom seems to be a promising candidate for exploring VIC. The manipulation of VIC with photoassociation may be important for controlling decoherence and dissipation in cold molecules.

"This similar technique can also be applicable to other cold atoms in the microkelvin energy regime," says lead researcher Bimalendu Deb. The proposed scheme may open up new ways to control decoherence in cold molecules and affect atom–molecule conversion, paving future studies on quantum information processing, he adds.

The authors of this work are from: Department of Materials Science, and Department of Materials Science and Raman Center for Atomic, Molecular and Optical Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata, India. _


  1. Das, S. et al. Vacuum-induced coherence in ultracold photoassociative rovibrational excitations. Phys. Rev. A. 85, 011401(R) (2012) | ADS |