Quantum sensors for microscopic tunneling systems

Abstract The anomalous low-temperature properties of glasses arise from intrinsic excitable entities, so-called tunneling Two-Level-Systems (TLS), whose microscopic nature has been baffling solid-state physicists for decades. TLS have become particularly important micro-fabricated quantum devices such as superconducting qubits, where they are a major source decoherence. Here, we present method to characterize individual in virtually arbitrary materials deposited thin films. material is used the dielectric capacitor that shunts Josephson junction qubit. In hybrid system qubit serves an interface detect and control TLS. We demonstrate spectroscopic measurements resonances, evaluate their coupling applied strain DC-electric fields, find evidence strong interaction between coherent sample material. Our approach opens avenues spectroscopy investigate structure defects develop low-loss dielectrics urgently required advancement computers.