Evolution of Nanowire Transmons and Their Quantum Coherence in Magnetic Field

Understand

We present an experimental study of nanowire transmons at zero and applied in-plane magnetic field.

• With Josephson non-linearities provided by the nanowires, our qubits operate at higher magnetic fields than standard transmons.
• Nanowire transmons exhibit coherence up to 70 mT, where the induced superconducting gap in the nanowire closes.
• We demonstrate that on-chip charge noise coupling to the Josephson energy plays a dominant role in the qubit dephasing.