# Transmon Qubit Calculator

With this calculator you can convert between charging energy (E_{c}) and total capacitance (C_{Σ}), between Josephson energy (E_{J}), Josephson inductance (L_{J}), junction critical current (I_{c}) or room temperature junction resistance (R), and from charging and Josephson energies calculate relevant qubit transition frequencies.

#### Parameter Description

E_{c} |
Charging energy | |

C_{Σ} |
Total capacitance | |

E_{J} |
Junction/SQUID Josephson energy | |

L_{J} |
Junction/SQUID Josephson inductance | |

I_{c} |
Junction/SQUID critical current | |

R | Junction/SQUID room temperature resistance for 30/40 nm thin Al films | |

ω_{g-e} |
Maximal qubit ground (g) to first excited state (e) transition frequency | |

ω_{e-f} |
Maximal qubit first (e) to second excited state (f) transition frequency | |

ω_{g-f} |
Maximal qubit ground (g) to second excited state (f) transition frequency | |

α | Qubit anharmonicity == E_{c} |