A multistep laser excitation scheme was used to access the last, least bound levels close to the lowest asymptote $3s+3s$ with the molecular states $X{}^{1}{\ensuremath{\Sigma}}_{g}^{+}$ and $a{}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ of ${\mathrm{Na}}_{2}$ . All singlet levels within the last $10 {\mathrm{cm}}^{\ensuremath{-}1}$, and some triplet levels with sufficient singlet admixture, were observed. The level energies were determined with uncertainties of less than 22 MHz with respect to the dissociation limit. The hyperfine structure was resolved, and asymmetric line shapes due to predissociation by tunneling through the rotational barrier or electronic state coupling were recorded for levels above the dissociation limit.A multistep laser excitation scheme was used to access the last, least bound levels close to the lowest asymptote $3s+3s$ with the molecular states $X{}^{1}{\ensuremath{\Sigma}}_{g}^{+}$ and $a{}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ of ${\mathrm{Na}}_{2}$. All singlet levels within the last $10 {\mathrm{cm}}^{\ensuremath{-}1}$, and some triplet levels with sufficient singlet admixture, were observed. The level energies were determined with uncertainties of less than 22 MHz with respect to the dissociation limit. The hyperfine structure was resolved, and asymmetric line shapes due to predissociation by tunneling through the rotational barrier or electronic state coupling were recorded for levels above the dissociation limit.

Physical Review AMay 1, 199923 citations

The short version

Andreas H. Trabesinger

Nature PhysicsJun 1, 20096 citations

Quantum Radar: Challenges and Outlook: An Overview of the State of the Art

David Luong, Bhashyam Balaji, Sreeraman Rajan

Quantum radar is a fledgling new technology that promises gains in detection performance. However, there are challenges standing in the way of their implementation. In this article, three classes of quantum radars are discussed: quantum interferometric radar, quantum illumination radar, and quantum two-mode squeezing (QTMS) radar. Of these, the last-named is the closest to being implemented in real life, though it is by no means the last word on the subject. In conclusion, we find that quantum radars are at least worth studying further.Quantum radar is a fledgling new technology that promises gains in detection performance. However, there are challenges standing in the way of their implementation. In this article, three classes of quantum radars are discussed: quantum interferometric radar, quantum illumination radar, and quantum two-mode squeezing (QTMS) radar. Of these, the last-named is the closest to being implemented in real life, though it is by no means the last word on the subject. In conclusion, we find that quantum radars are at least worth studying further.

IEEE Microwave MagazineAug 4, 202312 citations

A bit of both

Smitha Vishveshwara

Nature PhysicsJun 1, 20119 citations

Strange world at a simple level

Colin Jack

David Lindley's book on interpretations of quantum theory won wide acclaim when it was first published in the US last year. Infuriatingly, the original Basic Books hardback remained almost unobtainable in Europe. I know of at least one major UK bookshop that has been trying to reorder it since last May, so this paperback edition is most welcome. Lindley does an excellent job of describing the conceptual problems of quantum mechanics in a way that is accessible to the layperson. He sets out to tell the tale in a logical rather than a historical order, yet we get a good flavour of the way in which the scientific consensus has progressed. We are also reminded how the prejudices of some of the main contributors, notably Einstein, Bohr and David Bohm, may have been just as influential as their scientific contributions.David Lindley's book on interpretations of quantum theory won wide acclaim when it was first published in the US last year. Infuriatingly, the original Basic Books hardback remained almost unobtainable in Europe. I know of at least one major UK bookshop that has been trying to reorder it since last May, so this paperback edition is most welcome. Lindley does an excellent job of describing the conceptual problems of quantum mechanics in a way that is accessible to the layperson. He sets out to tell the tale in a logical rather than a historical order, yet we get a good flavour of the way in which the scientific consensus has progressed. We are also reminded how the prejudices of some of the main contributors, notably Einstein, Bohr and David Bohm, may have been just as influential as their scientific contributions.

Physics WorldApr 1, 19970 citations

A multistep laser excitation scheme was used to access the last, least bound levels close to the lowest asymptote

3s+3s

with the molecular states $X{}^{1}{\ensuremath{\Sigma}}_{g}^{+}$ and $a{}^{3}{\ensuremath{\Sigma}}_{u}^{+}$ of

{\mathrm{Na}}_{2}

. All singlet levels within the last $10 {\mathrm{cm}}^{\ensuremath{-}1}$, and some triplet levels with sufficient singlet admixture, were observed. The level energies were determined with uncertainties of less than 22 MHz with respect to the dissociation limit. The hyperfine structure was resolved, and asymmetric line shapes due to predissociation by tunneling through the rotational barrier or electronic state coupling were recorded for levels above the dissociation limit.