qcheff.models.duffing.duffing_chain_utils

Module Contents

Classes

DuffingChain

Implements a linear chain of N Duffing Oscillator qubits. This simple example assumes the qubits are all coupled to their nearest neighbors with the different coupling strenghs g.

Functions

create_duffing_chain_system	Factory function for Duffing chain
create_linear_spectrum_zz_chain	Creates a linear chain of Duffing Oscillators. The ends have anharmonicity alpha, modeling transmons. The remaining are linear resonators, with their frequencies distributed in a V shape.
duffing_chain_num_ham	Numerical Hamiltonian in full Hilbert space for a Duffing Oscillator chain.
duffing_chain_qutip_ham	Numerical Hamiltonian in full Hilbert space for a Duffing Oscillator chain.
duffing_chain_scq_hilbertspace	SCQubits Hamiltonian for a Duffing Oscillator chain.

API

class DuffingChain

Implements a linear chain of N Duffing Oscillator qubits. This simple example assumes the qubits are all coupled to their nearest neighbors with the different coupling strenghs g.

qubits: list[qcheff.duffing.duffing_utils.DuffingOscQubit]

None

couplings: list[float]

None

ntrunc: int

None

create_duffing_chain_system(omegas, alphas, couplings, ntrunc: int = 3)

Factory function for Duffing chain

create_linear_spectrum_zz_chain(delta1: float, delta2: float, alpha1: float = -0.3, alpha2: float = -0.3, num_resonators: int = 1, omega_res: float = 5, delta_omega_res: float = 0.6, g: float = 0.1, ntrunc: int = 3, debug: bool = False) → qcheff.models.duffing.duffing_chain_utils.DuffingChain

Creates a linear chain of Duffing Oscillators. The ends have anharmonicity alpha, modeling transmons. The remaining are linear resonators, with their frequencies distributed in a V shape.

duffing_chain_num_ham(example: qcheff.models.duffing.duffing_chain_utils.DuffingChain)

Numerical Hamiltonian in full Hilbert space for a Duffing Oscillator chain.

example: DuffingChain The example system

duffing_chain_qutip_ham(example: qcheff.models.duffing.duffing_chain_utils.DuffingChain)

Numerical Hamiltonian in full Hilbert space for a Duffing Oscillator chain.

example: DuffingChain The example system

duffing_chain_scq_hilbertspace(example: qcheff.models.duffing.duffing_chain_utils.DuffingChain)

SCQubits Hamiltonian for a Duffing Oscillator chain.

Since SCQubits comes with a Kerr oscillator class, we can use it to define the qubits. However, the Kerr oscillator Hamiltonian has different constants, so we need to adjust the sign of the anharmonicity and divide by 2.