# qpdk

> QPDK is an open-source process design kit (PDK) for superconducting quantum RF applications built on gdsfactory. It provides parametric quantum circuit components (transmon qubits, CPW resonators, Josephson junctions, etc.), analytical S-parameter models, routing utilities, and test-chip examples. Source: https://github.com/gdsfactory/quantum-rf-pdk; published as `qpdk` on PyPI.


gdsfactory

## Pages in this subsection

- [QPDK Models](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/all_models.html.md): This notebook evaluates and plots a selection of the S-parameter models in `qpdk.models`.
- [Circuit Simulation with QPDK](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/circuit_simulation_demo.html.md): This notebook demonstrates how to perform circuit simulations using the `qpdk` models and the `sax` ...
- [Differentiable Transmon Circuit Simulation with Circulax](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/circulax_transmon_optimization.html.md): This notebook demonstrates how to use
- [COMSOL Full-Wave Simulation of a Coupled Quarter-Wave Resonator](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/comsol_cpw_resonator.html.md): The shortest path from a QPDK layout to a driven COMSOL result: build a coupled quarter-wave
- [COMSOL transmon capacitance and field](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/comsol_qubit_capacitance.html.md): This tutorial walks the path end to end: build a QPDK double-pad
- [Elmer Capacitance Extraction of an Interdigital Capacitor](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/elmer_capacitance_interdigital.html.md): This notebook runs a quasi-static electrostatic solve with Elmer FEM for two
- [FEM Dataset Lookup in SAX Models](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/fem_dataset_lookup.html.md): Circuit models of superconducting layouts need electrostatic quantities such as
- [HFSS Driven Modal Simulation of an Interdigital Capacitor](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/hfss_driven_capacitor.html.md): This notebook demonstrates how to set up and run a driven modal (S-parameter)
- [HFSS Eigenmode Simulation of a CPW Resonator](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/hfss_eigenmode_resonator.html.md): This notebook demonstrates how to set up and run an eigenmode simulation
- [Q2D Cross-Section Impedance of a Coplanar Waveguide](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/hfss_q2d_cpw_impedance.html.md): This notebook demonstrates how to extract the characteristic impedance
- [JAX Backend Comparison for Quantum Circuit Simulation](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/jax_backend_comparison.html.md): This notebook loads recorded CPU, CUDA, and Apple Silicon (MPS) measurements
- [Josephson traveling-wave parametric amplifiers with JosephsonCircuits.jl](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/josephsoncircuits_twpa.html.md): A traveling-wave parametric amplifier (TWPA) uses a chain of Josephson junctions to amplify a weak s...
- [Call qpdk from MATLAB](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/matlab_integration.html.md): This notebook demonstrates calling `qpdk` (and through it, `gdsfactory`) **directly from MATLAB**
- [Model Comparison to Qucs-S](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/model_comparison_to_qucs.html.md): This notebook compares the S-parameter models from qpdk (using sax) against reference
- [Monte Carlo Fabrication Tolerance Analysis](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/monte_carlo_fabrication_tolerance.html.md): This notebook demonstrates how to run a circuit-level SAX simulation of the
- [Transmon Qubit Design with NetKet](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/netket_transmon_design.html.md): This notebook demonstrates how to use
- [Optuna Optimization of Interdigital Capacitor](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/optimize_capacitor_optuna.html.md): This example demonstrates using Optuna to optimize an interdigital capacitor
- [Dispersive Shift of a Transmon–Resonator System with Pymablock](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/pymablock_dispersive_shift.html.md): This notebook demonstrates how to use
- [Pulse-Level Simulation of Superconducting Qubits with QuTiP-QIP](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/qutip_qip_pulse_simulation.html.md): This notebook demonstrates how to use
- [Resonator frequency estimation models](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/resonator_frequency_model.html.md): This example demonstrates estimating resonance frequencies of superconducting microwave resonators u...
- [Dispersive Shift of a Transmon–Resonator System with scQubits](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/scqubits_parameter_calculation.html.md): This notebook demonstrates how to use
- [CPW parametric amplifiers: layout and circuit models](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/vacask_cpw_parametric_amplifier.html.md): A flux-pumped JPA uses a SQUID to modulate the resonance of a distributed
- [Lumped Josephson parametric amplifiers with VACASK](https://gdsfactory.github.io/quantum-rf-pdk/notebooks/vacask_lumped_parametric_amplifier.html.md): A parametric amplifier uses a strong pump and a nonlinear inductance to

## Optional

- [Top-level llms.txt](https://gdsfactory.github.io/quantum-rf-pdk/llms.txt): Complete documentation index.