Observation of Long Coherence Time in a Superconducting Transmon Qubit

Abstract

The coherence time of superconducting qubit has been improved by many orders of magnitudes during last decades after its first demonstration in 1999.This improvement in the coherence was one of the key factors that have enabled implementation of a practical quantum information processing device, high fidelity gate operations, and possibility of fault-tolerant quantum computing. Here we report an observation of a coherence time over100 microseconds in our transmon qubit. The long coherence time was achieved by improvements in both device fabrication and measurement system configuration.