Meeting the Snob Factor

The best journals employ a snob factor as a first cut to limit the deluge of submitted manuscripts that go out for peer review.  The editor uses the "desk reject" for potential papers that don't look interesting.  Then, the reviewers are asked to evaluate a manuscript's significance to the field prior commenting on the technical details.  These two layers of subjective assessment can doom a manuscript, relegating it to a polite rejection: the work might be technically correct, but it is not of broad enough interest.

One such journal is Optics Letters, published by the Optical Society of America.  Though it is eclipsed by the new OSA journal Optica in its impact, it is still a highly selective and respectable publication.  Recently, we beat the odds by receiving an acceptance letter (subject to minor revision) along with the initial reviews.  The preprint of the paper can be viewed at https://arxiv.org/pdf/1809.01216.pdf

While the paper is based on some esoteric principles, it provides the experimentalist with a recipe for adding one state to the simple model commonly used in the field to correct for the infinite number of states that are omitted for bovious practical reasons.  This magical state is a proxy for those infinite numbers of states that are ignored.  The figure shows a plot corresponding to the uncorrected model (left) and the corrected one (right).  The nice smooth green background and the sharp red along the diagonal is the signature of success.  We thought it cool and useful that such a proxy state could fix a problem that has been plaguing nonlinear-optical measurements for decades.  For once, the editor and reviewers agree.

Here is a summary of the reviews:

Reviewer 1:

The manuscript represents an important advance in the calculation of nonlinear susceptibilities because it presents for the first time a method for dealing with the difficult continuum states present in realistic models of molecules. Ignoring these states leads, as the authors identify, to large errors in the calculations while, perhaps surprisingly, a single proxy state allows one to eliminate these errors to a large degree. This proxy state is not just a mathematical fudge, it is defined through physically measurable quantities. I therefore strongly recommend publication. 

Reviewer 2:

This is an interesting work discussing corrections to polarizability and hyperpolarizability calculations for limited state models that can be made using a single proxy state.  The conclusions are well supported by the calculations and this will find significant interest in its community.  

New Physical Review Letters Paper is out

Researchers at Washington State University use Patterns to set Limits on Light/Matter Interactions

 

Physicists Rick Lytel, Sean Mossman, Ethan Crowell and Mark Kuzyk at Washington State University are developing general principles that can be applied to making new materials that harness light.   Beefed up light-matter interactions can be used to make higher-contrast medical images, more effectively burn cancer cells while leaving healthy ones intact, suppress the twinkle of stars in telescopes, supercharge the internet, make lasers more colorful and effortlessly process complex images.  The new has appeared in the August 18^th 2017 issue of Physical Review Letters.

Researchers typically model each new candidate material with complex equations that are difficult to interpret.  Rather than evaluate specific materials using this obtuse formalism, the WSU team instead studies the structure of the equations to search for patterns that hint at the largest possible response.  Since the equations are intractable, the researchers instead throw metaphoric darts at the target, but constrain the trajectories using the sum rules -- physical laws that must be obeyed by a quantum system.  After many throws, and applying a filter that takes into account the effect of molecule size, a pattern comes into focus.

The pattern reveals the true fundamental limits to be about 30% lower than previously calculated and suggests that a potentially new design paradigm will be required to get to the limit.  Ongoing work is aimed at translating the physicists’ esoteric findings into rules that can be used by chemists, materials scientists and nanotechnologists to make better materials.

The present work resolves several puzzles.  The theory of the fundamental limits of light/matter interaction strength predicted a ceiling that was almost 50% higher than all theoretical models, suggesting that exotic materials were needed to bridge the gap.  The new work shows that such unphysical quantum systems are not required to reach the limits and that exotic systems will likely obey the same limit.  Furthermore, infinities in the older incomplete theory – warning flags in physics of theoretical pathologies -- have been excluded by the new results.

While the present work has practical implications for new technologies, the search for patterns generated by constrained random sampling is a powerful tool that can be applied to understanding the underlying structure of complex theories.  In future work, the WSU researchers plan to apply this approach to a holistic investigation of the combined properties of a material needed for specific applications, and identifying the path for getting there.