Temperature square dependence of the low frequency 1/f charge noise in the Josephson junction qubits

TL;DR

This study demonstrates a T^2 temperature dependence of 1/f charge noise in Josephson charge qubits, supporting the hypothesis of a common origin with quantum f noise and explaining dephasing mechanisms.

Contribution

It provides experimental evidence for the T^2 dependence of 1/f noise and links it to dephasing in Josephson charge qubits, advancing understanding of noise sources.

Findings

T^2 dependence of 1/f noise confirmed experimentally

Dephasing explained by low frequency 1/f noise

Supports common origin hypothesis for charge and quantum f noise

Abstract

To verify the hypothesis about the common origin of the low frequency 1/f noise and the quantum f noise recently measured in the Josephson charge qubits, we study temperature dependence of the 1/f noise and decay of coherent oscillations. T^2 dependence of the 1/f noise is experimentally demonstrated, which supports the hypothesis. We also show that dephasing in the Josephson charge qubits off the electrostatic energy degeneracy point is consistently explained by the same low frequency 1/f noise that is observed in the transport measurements.