Monium
Get Monium

iOS · Android

Superconducting qubits, in your hand.

Monium brings transmons, tunable transmons, and fluxonium to mobile — interactive energy spectra, wavefunctions, matrix elements, and coherence times, computed on-device.

  • Transmon
  • Tunable transmon
  • Fluxonium
Download on the App Store Coming soon to Google Play
Monium showing a fluxonium's wavefunctions over its double-well potential
What it does

A research toolkit that fits in your pocket.

  • Energy spectra

    Eigenenergies versus any swept parameter — flux, EJ, charge offset — with transition readouts.

  • Wavefunctions

    Plot |ψ|², Re ψ, Im ψ, or the charge basis over the qubit potential, level by level.

  • Matrix elements

    Operator matrix-element heatmaps with magnitude, real, and imaginary views and LaTeX labels.

  • Matrix-element scans

    Watch individual matrix elements evolve as you sweep a circuit parameter.

  • Coherence times

    Per-channel T₁ and Tφ plus effective T₁/T₂ versus the swept parameter, on a log scale.

  • Convergence built in

    An always-on verdict tells you when a result is trustworthy, with one-tap refinement.

See it

Every view, computed live on-device.

  • Monium — Energy spectrum
    Energy spectrum Levels vs. flux
  • Monium — Circuit & Hamiltonian
    Circuit & Hamiltonian The physics, defined
  • Monium — Wavefunctions
    Wavefunctions ψ over the potential
  • Monium — Matrix elements
    Matrix elements Operator heatmap
  • Monium — Element scan
    Element scan Elements vs. parameter
  • Monium — Coherence
    Coherence T₁ / T₂ channels
Depth

Built for theorists and experimentalists.

Monium is for exploring the physics — convergence you can check and matrix elements in full — and it meets the bench halfway, turning the quantities you measure into trustworthy spectra.

  1. Monium’s parameter-entry sheet converting between EJ, critical current, Josephson inductance and normal-state resistance
    For the bench

    Enter what you measure

    Set the energies the way your wafer reports them: the junction energy from critical current I_c, Josephson inductance L_J, or room-temperature normal-state resistance R_n (via Ambegaokar–Baratoff, with a cryo/room correction and a material gap — aluminium by default); the charging energy from a capacitance; the inductive energy from an inductance. On a tunable transmon, split E_J into its two junctions and the SQUID asymmetry follows.

  2. Monium’s convergence sheet reporting an estimated relative error and a re-verify control
    Convergence

    Check for convergence issues

    Every spectrum carries a convergence check. Monium re-diagonalizes at a larger cutoff or finer grid, estimates the relative error, and flags levels that may not be converged — good evidence, not a guarantee. Re-verify on demand.

  3. Monium’s matrix-element plot options: operator, component, and per-element selection
    Matrix elements

    Matrix elements, your way

    Inspect ⟨i|Ô|j⟩ for the operator you care about — n̂, φ̂, cos φ, or sin φ — as real part, imaginary part, magnitude, or |·|², and toggle exactly which transitions appear.

Source of truth

The same physics as scqubits — on your phone.

Monium’s engine is ported from and cross-validated against scqubits, the open-source library for superconducting qubits. Every spectrum, matrix element, and coherence time is checked against the Python reference, so the numbers match the literature — not a toy model.

Explore scqubits

Now on the App Store.

Monium is available on the App Store for iPhone. The Android version is coming soon.

Download on the App Store Coming soon to Google Play