Quantum-critical circuits: a new Nature pubication

In a collaboration with Stanford, researchers in the EQP 'Momentum' Group of the Institute of Physics studied how electrons 'cease to exist' in a nano-circuit. Researchers Pascu Moca and Gergely Zarand (group leader) collaborated with the experimental group of David Goldhaber-Gordon at Stanford to realize and investigate in detail a so-called quantum critical state by using nano-electronic circuits.

The Stanford group built an artificial atom, attached to external electrodes. With the help of the computations of the Momentum group, they managed to tune the circuit to a state, where the artificial atom destroys every electron that passes through it. They observed in detail how – in agreement with the theoretical computations – this new quantum state forms where electrons in the electrodes loose their usual properties and cease to exist in some sense [Keller et al, Nature 526, 237 (2015)].

A. J. Keller, L. Peeters, C. P. Moca, I. Weymann, D. Mahalu, V. Umansky, G. Zaránd & D. Goldhaber-Gordon: Universal Fermi liquid crossover and quantum criticality in a mesoscopic system, Nature 526, 237 (2015).