qtcad.qubit.edsr module

Class related to Electric-dipole spin resonance (EDSR)

class qtcad.qubit.edsr.MicromagnetEDSR(d, subdevice=None)

Bases: qubit.core.edsr.MicromagnetEDSR

EDSR object where coupling between spin and orbital degrees of freedom is generated via a micromagnet.

__init__(d, subdevice=None)

Constructor of the MicromagnetEDSR class.

Parameters

  • d (Device object) – The full device, over which Poisson’s equation is solved.

  • subdevice (SubDevice object or None, optional) – The subdevice over which Schrodinger’s equation is solved. If None, the envelope functions are defined over the full device.

solve(gate_biases, gate, homo_B, varying_B, base_bias=None)

Compute system and drive Hamiltonian for a electron subject to a coupling between its spin and orbital degrees of freedom and the electric field produced by an modulated voltage applied to a gate.

Parameters

  • gate_biases (1D array) – Potentials to be applied to a gate.

  • gate (string) – Name of the gate where the voltage will be modulated.

  • coupling_params – Parameters to be passed to coupling method. Coupling method is responsible for computing the coupling between spin and orbital degrees of freedom.

  • base_bias (float) – The value of the voltage applied to the gate before modulations are induced. This value should be included in V. As a default the the first value of V will be taken.

Returns

tuple – a tuple (H0, UU), where H0 (2D array) is the system Hamiltonian matrix (including spin) in its eigenbasis (diagonal) (the energies are reset so that the ground state has an energy of 0) and UU (3D array) is the drive operator in the eigenbasis of the system Hamiltonian for each voltage applied to the gate.

class qtcad.qubit.edsr.SpinOrbitEDSR(d, subdevice=None)

Bases: qubit.core.edsr.SpinOrbitEDSR

EDSR object where coupling between spin and orbital degrees of freedom is generated via the linear Rashba spin-orbit coupling.

__init__(d, subdevice=None)

Constructor of the SpinOrbitEDSR class.

Parameters

  • d (Device object) – The full device, over which Poisson’s equation is solved.

  • subdevice (SubDevice object or None, optional) – The subdevice over which Schrodinger’s equation is solved. If None, the envelope functions are defined over the full device.

solve(gate_biases, gate, soc_strength, base_bias=None)

Compute system and drive Hamiltonian for a electron subject to coupling between its spin and orbital degrees of freedom via the linear Rashba spin-orbit coupling and the electric field produced by a modulated voltage applied to a gate.

Parameters

  • gate_biases (1D array) – Potentials to be applied to a gate.

  • gate (string) – Name of the gate where the voltage will be modulated.

  • soc_strength (float) – Spin-orbit coupling strength.

  • base_bias (float) – The value of the voltage applied to the gate before modulations are induced. This value should be included in V. As a default the the first value of V will be taken.

Returns

tuple – a tuple (H0, UU) where H0 (2D array) is the system Hamiltonian matrix (including spin) in its eigenbasis (diagonal) and UU (3D array) is the drive operator in the eigenbasis of the system Hamiltonian for each voltage applied to the gate.