[1] Ecole Polytech Fed Lausanne, Inst Phys, CH-1015 Lausanne, Switzerland
[2] Columbia Univ, Dept Appl Phys & Appl Math, New York, NY 10027 USA
[3] Columbia Univ, Dept Elect Engn, New York, NY 10027 USA
[4] Lomonosov Moscow State Univ, Fac Phys, Moscow 119991, Russia
[5] Russian Quantum Ctr, Moscow 143025, Russia