Here's another article that proposes to explain why it works: http://aip.scitation.org/doi/full/10.1063/1.4953807 http://aip.scitation.org/doi/full/10.1063/1.4

Here's another article that proposes to explain why it works: http://aip.scitation.org/doi/full/10.1063/1.4953807 http://aip.scitation.org/doi/full/10.1063/1.4953807