Updated demo_legacy_explorer.ipynb

[ahkatlio]

Fixed the issues:

Gave a detailed description:

We are creating two quantum systems using the scq library.

1. Fluxonium: This is a type of superconducting circuit, a quantum system that can be used as a qubit (the basic unit of quantum information). The parameters EJ, EC, EL, flux, cutoff, and truncated_dim are specific to the physics of the Fluxonium system.

2. Oscillator: This represents a quantum harmonic oscillator, a system that, when undisturbed, oscillates at some steady frequency. E_osc is the energy of the oscillator and truncated_dim is the dimension after truncation.

Here's a brief explanation of the parameters:

• EJ, EC, EL: Energy scales for the Fluxonium system (Josephson, charging, and inductive energy respectively).
• flux: External magnetic flux applied to the Fluxonium circuit.
• cutoff: The maximum number of charge states included in the Hilbert space.
• truncated_dim: The dimension of the Hilbert space after it has been truncated.
• E_osc: Energy of the quantum harmonic oscillator.

the code I fixed:

# Define the interaction term
interaction_term = InteractionTerm(
    g_strength=0.2,
    operator_list=[(0, qbt.n_operator()), (1, osc.creation_operator() + osc.annihilation_operator())]
)

# Define the subsystem list
subsystem_list = [qbt, osc]

# Get the Hamiltonian
hamiltonian = interaction_term.hamiltonian(subsystem_list)

# Print the Hamiltonian
dressed_hamiltonian = hilbertspace.hamiltonian()
dressed_hamiltonian

param_name = r'$\Phi_{ext}/\Phi_0$'
param_vals = np.linspace(-0.5, 0.5, 100)

subsys_update_list = [qbt]

def update_hilbertspace(param_val):
    qbt.flux = param_val

sweep = ParameterSweep(
    hilbertspace=hilbertspace,
    paramvals_by_name={param_name: param_vals},
    update_hilbertspace=update_hilbertspace,
    evals_count=10,
    subsys_update_info={'qbt': subsys_update_list},
    num_cpus=4
)

# Create an Explorer object
explorer = Explorer(sweep=sweep, ncols=3)

qbt1 = scq.Transmon(
     EJ=25.0,
     EC=0.2,
     ng=0,
     ncut=30,
     truncated_dim=3)

qbt2 = scq.Transmon(
     EJ=15.0,
     EC=0.15,
     ng=0,
     ncut=30,
     truncated_dim=3)

resonator = scq.Oscillator(
    E_osc=5.5,
    truncated_dim=4)

hilbertspace = HilbertSpace([qbt1, qbt2, resonator])

g1 = 0.1  # coupling resonator-CPB1 (without charge matrix elements)
g2 = 0.2  # coupling resonator-CPB2 (without charge matrix elements)

interaction1 = InteractionTerm(
    g_strength=g1,
    operator_list=[(0, qbt1.n_operator()), (2, resonator.creation_operator() + resonator.annihilation_operator())],
    add_hc=False
)

interaction2 = InteractionTerm(
    g_strength=g2,
    operator_list=[(1, qbt2.n_operator()), (2, resonator.creation_operator() + resonator.annihilation_operator())],
    add_hc=False
)

interaction_list = [interaction1, interaction2]
hilbertspace.interaction_list = interaction_list

# Print the interaction terms
for i, interaction in enumerate(interaction_list, 1):
    print(f"Interaction {i}:")
    print(interaction)

param_name = r'$\Phi_{ext}/\Phi_0$'
param_vals = np.linspace(0.0, 1.0, 150)

subsys_update_list = [qbt1, qbt2]


def update_hilbertspace(param_val):     # function that shows how Hilbert space components are updated
    qbt1.EJ = 30*np.abs(np.cos(np.pi * param_val))
    qbt2.EJ = 40*np.abs(np.cos(np.pi * param_val * 2))
    

sweep = ParameterSweep(
    hilbertspace=hilbertspace,
    paramvals_by_name={param_name: param_vals},
    update_hilbertspace=update_hilbertspace,
    evals_count=10,
    subsys_update_info={'qbt': subsys_update_list},
    num_cpus=4
)

They are not showing any errors

[review-notebook-app]

Check out this pull request on 

See visual diffs & provide feedback on Jupyter Notebooks.

---

Powered by ReviewNB