%0 Journal Article
%T Quantum superposition of three macroscopic states and superconducting qutrit detector
%A V. I. Shnyrkov
%A A. A. Soroka
%A O. G. Turutanov
%J Physics
%D 2011
%I arXiv
%R 10.1103/PhysRevB.85.224512
%X Superconducting quantum coherent circuits have opened up a novel area of fundamental low-temperature science since they could potentially be the element base for future quantum computers. Here we report a quasi-three-level coherent system, the so-called superconducting qutrit, which has some advantages over a two-level information cell (qubit), and is based on the qutrit readout circuit intended to measure individually the states of each qubit in a quantum computer. The designed and implemented radio-frequency superconducting qutrit detector (rf SQUTRID) with atomic-size ScS-type contact utilizes the coherent-state superposition in the three-well potential with energy splitting Delta E_01/k_B=1.5 K at the 30th quantized energy level with good isolation from the electromagnetic environment. The reason why large values of Delta E_01 (and thus using atomic-size Nb-Nb contact) are required is to ensure an adiabatic limit for the quantum dynamics of magnetic flux in the rf SQUTRID.
%U http://arxiv.org/abs/1111.6571v3