fock_state

Contains classes for representing in excited states of some bosonic mode. The creation/annihilation operators have a symbolic variable which can for example be the frequency of the excited state.

class qualg.fock_state.FockOp(mode, variable, creation=True)

__init__(mode, variable, creation=True)

Represents an creation/annihilation operator in a given mode with a given variable representing for example the frequency of the excitation.

Parameters

• mode (str) – The mode of the excitation

• variable (str) – The variable describing the continous variable

• creation (bool) – Whether this is a creation operator or not (annihilation).

dagger()

Complex conjugate of the operator.

replace_var(old_variable, new_variable)

Replaces a variable with another.

get_variables()

Returns the variable of this operator.

class qualg.fock_state.FockOpProduct(fock_ops=None)

__init__(fock_ops=None)

A product of excitation operators (FockOp).

Parameters

fock_ops (list of FockOp) – The product of fock operators.

dagger()

Complex conjugate of the operator.

variables_in_mode(mode)

Get the variables in a given mode.

variables_by_modes()

Get a dictionay of variables per modes.

replace_var(old_variable, new_variable)

Replaces a variable with another.

get_variables()

Returns the variable of this operator.

class qualg.fock_state.BaseFockState(fock_ops=None)

__init__(fock_ops=None)

A base state represented by excitations from vacuum.

Parameters

fock_ops (FockOpProduct or list of FockOp) – The product of fock operators.

property shape

Returns the shape of the state, e.q. (2,) for a qubit.

None means that the shape is undefined, e.g. if the state is infinite-dimensional.

inner_product(other)

Takes the inner product with another BaseState.

Parameters

other (BaseState) – The right hand side of the inner product.

Returns

The inner product

Return type

class`~.scalar.Scalar`

tensor_product(other)

Takes the tensor product with another BaseState.

Parameters

other (BaseState) – The right hand side of the tensor product.

Returns

The tensor product

Return type

BaseState

replace_var(old_variable, new_variable)

Replaces a variable with another.

get_variables()

Returns the variable of this operator.

qualg.fock_state.assert_fock_op(op)

Asserts that an object is a fock operator.