Simulations using PALACE

Once the design has been completed using Qiskit-Metal, the design object can be used to run simulations in AWS Palace. Currently, SQDMetal supports:

  • Capacitance matrix simulations

  • RF s-parameter simulations

  • Eigenmode simulations

The raw data can be viewed via ParaView or our in-built visualisation class.

Installation

Make sure to install the gmsh in the Python environment. Now to run simulations in Palace, the distribution must be installed either on a local computer or a cluster. We offer several implementations for a local PC:

Helper utility modules

Usage (local PC)

Note

We recommend browsing our worked examples for further details beyond the example usage shown below.

from SQDMetal.PALACE.Eigenmode_Simulation import PALACE_Eigenmode_Simulation
from SQDMetal.Utilities.Materials import MaterialInterface

#Eigenmode Simulation Options
user_defined_options = {
                "mesh_refinement":  0,                             #refines mesh in PALACE - essetially divides every mesh element in half
                "dielectric_material": "silicon",                  #choose dielectric material - 'silicon' or 'sapphire'
                "starting_freq": 5e9,                              #starting frequency in Hz
                "number_of_freqs": 1,                              #number of eigenmodes to find
                "solns_to_save": 1,                                #number of electromagnetic field visualizations to save
                "solver_order": 2,                                 #increasing solver order increases accuracy of simulation, but significantly increases sim time
                "solver_tol": 1.0e-8,                              #error residual tolerance foriterative solver
                "solver_maxits": 200,                              #number of solver iterations
                "fillet_resolution":12,                            #number of vertices per quarter turn on a filleted path
                "palace_dir":"~/spack/opt/spack/linux-ubuntu24.04-zen2/gcc-13.3.0/palace-develop-36rxmgzatchgymg5tcbfz3qrmkf4jnmj/bin/palace",#"PATH/TO/PALACE/BINARY",
                "num_cpus": 16                                     #number of cpus used in simulation
                }

#Create the Palace Eigenmode simulation
eigen_sim = PALACE_Eigenmode_Simulation(name ='x-mon_test',                                         #name of simulation
                                        metal_design = design,                                      #feed in qiskit metal design
                                        sim_parent_directory = "",                                  #choose directory where mesh file and config file are saved
                                        mode = 'simPC',                                             #choose simulation mode 'HPC' or 'simPC'
                                        meshing = 'GMSH',                                           #choose meshing 'GMSH' or 'COMSOL'
                                        user_options = user_defined_options,                        #provide options chosen above
                                        create_files = True)                                        #create mesh, config and HPC batch files

#Add in metals from layer 1 of the design file
eigen_sim.add_metallic(1)

#Add in ground plane for simulation
eigen_sim.add_ground_plane()

#Add in the Josephson junction as a lumped port
eigen_sim.create_port_JosephsonJunction('junction', L_J=4.3e-9, C_J=10e-15)

#Fine-mesh x-mon
eigen_sim.fine_mesh_components(['x-mon'], min_size=8e-6, max_size=100e-6, taper_dist_min=10e-6, metals_only=False)

#Sets up the lossy interfaces for MA, SA and MS interfaces
eigen_sim.setup_EPR_interfaces(metal_air=MaterialInterface('Aluminium-Vacuum'), substrate_air=MaterialInterface('Silicon-Vacuum'), substrate_metal=MaterialInterface('Silicon-Aluminium'))

#Prepares the mesh file and config file
eigen_sim.prepare_simulation()

Details on viewing the data in the end are shown here.

Usage (HPC)

Here, some extra parameters need to be supplied. Specifically the path to a JSON file (supplied in the user option: “HPC_Parameters_JSON”) containing the parameters. Here is a template:

{
    "HPC_nodes": 4,
    "sim_memory": "300G",
    "sim_time": "20:00:00",
    "account_name": "sam",
    "palace_location": "/scratch/project/palace-sqdlab/Palace-Project/palace/build/bin/palace-x86_64.bin",
    "input_dir": "/scratch/project/palace-sqdlab/inputFiles/"
}

Functions

General functions

  • add_metallic

  • add_ground_plane

  • enforce_full_3D_simulation

  • set_xBoundary_as_proportion (note it uses that percentage on both sides. So 0.1 on a 1mm chip means 100um on negative side and 100um on positive side)

  • set_yBoundary_as_proportion

  • set_zBoundary_as_proportion

  • set_xBoundary_as_absolute

  • set_yBoundary_as_absolute

  • set_zBoundary_as_absolute

  • fine_mesh_features

  • fine_mesh_along_path (QM)

  • fine_mesh_in_rectangle

  • fine_mesh_components (QM)

  • enable_mesh_refinement

  • prepare_simulation

  • set_local_output_subdir

  • run

  • retrieve_data

  • retrieve_simulation_sizes

  • retrieve_simulation_sizes_from_file (Static)

  • open_mesh_gmsh

RF (Eigenmode and Frequency-Driven)

  • create_port_2_conds (QM)

  • create_port_JosephsonJunction (QM)

  • create_port_CPW_on_Launcher (QM)

  • create_port_CPW_on_Route (QM)

  • create_port_CPW_via_edge_point

  • create_CPW_feed_Uclip_on_Launcher (QM)

  • create_CPW_feed_Uclip_on_Route (QM)

  • set_port_impedance

  • create_waveport_on_boundary

  • setup_EPR_interfaces

  • add_kinetic_inductance

  • set_farfield

Eigenmode

  • set_freq_search

  • retrieve_field_plots

  • retrieve_EPR_data

  • retrieve_EPR_data_from_file

  • retrieve_mode_port_EPR

  • retrieve_mode_port_EPR_from_file

  • calculate_hamiltonian_parameters_EPR

  • calculate_hamiltonian_parameters_EPR_from_files

Frequency-Driven

  • set_port_excitation

  • set_freq_values

  • add_surface_current_source_region

  • retrieve_data_from_file

  • get_waveport_modes

  • get_waveport_modes_from_file

Capacitance Matrix

  • display_conductor_indices

  • calc_params_floating_Transmon

  • calc_params_floating_Transmon_from_files