<div dir="ltr"><div class="gmail_default" style="font-family:verdana,sans-serif;font-size:small;color:#333333">Any ideas on getting this non-pay walled?<br><a href="https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.28.240">https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.28.240</a></div></div>