Collapsed quantum model
Here we define functions to map the compilation problem into a quantum many-body system to simulate with qtealeaves.
In the collapsed mapping, we map the circuit in a q-dimensional qudits lattice. The coordinate labels the time-step, and the state of each qudit represents a possible time-step.
- class vulqano.quantummodels.collapsedquantummodel.CollapseMap(gates, circuit_times, n_t, n_q, reflection_sym=False)[source]
Maps the circuit states and operators from a (1+1)d lattice to a 1d lattice by collasing the qubit axis. Each possible gates configuration of a time step is mapped to a single local state.
Arguments
- gatesset of str
Gates allowed on the target machine (fictitious gates such as “idle “and “busy” are excluded).
- circuit_timesint
number of time steps allowed for the cicuit.
- n_tint
number of time steps represented in the lattice.
- n_qint
Number of qubits of the target machine.
- reflection_symbool, optional.
If true, only the supergates that represent time-steps invariant under a reflection on the qubits axis are included. Default is false. WARNING: needs reflection invariant infidelity and transition rules.
Attributes
- gatesset of str
Gates allowed on the target machine (fictitious gates such as “idle “and “busy” are excluded).
- circuit_timesint
number of time steps allowed for the cicuit.
- n_tint
number of time steps represented in the lattice.
- n_qint
Number of qubits of the target machine.
- collapsed_gateslist
A list of each possible time-step configuration, identified by a string “gate_0|gate_1|…|gate_n_q”.
- reflection_symbool
If true, only the supergates that represent time-steps invariant under a reflection on the qubits axis are included.
- build_driving_hamiltonian(rule, model, strength)[source]
Build a term in the driving Hamiltonian encoding a transition rule, add this Hamiltonian to the model.
Arguments
- rule: instance of DiscreteTransformationRule
Transition rule to be encoded as operator.
- modelqtealeaves.modeling.QuantumModel
QuantumModel describing the evolution Hamiltonian.
- strengthstring
Name of the coupling associated to the Hamiltonian term.
Returns
None.
- build_external_hamiltonian(model)[source]
Build an Hamiltonian that sets as idle all the lattice sites that are external to the ciruit area.
Arguments
- modelqtealeaves.modeling.QuantumModel
QuantumModel describing the evolution Hamiltonian.
Returns
None.
- build_infidelity_hamiltonian(hamiltonian, model, strength)[source]
Build an Hamiltonian that extimated the circuit infidelity, add this Hamiltonian to the model
Arguments
- modelqtealeaves.modeling.QuantumModel
QuantumModel describing the evolution Hamiltonian.
- strengthstring
Name of the coupling associated to the Hamiltonian.
Returns
None.
- build_initial_hamiltonian(state, model, strength, position=0)[source]
Build an Hamiltonian having the initial state as non-degenerate ground state, add this Hamiltonian to the model
Arguments
- modelqtealeaves.modeling.QuantumModel
QuantumModel describing the evolution Hamiltonian.
- strengthstring
Name of the coupling associated to the Hamiltonian.
Returns
None.
- collapse_hamiltonian_term(operator, prefactor, mask)[source]
Generate a collapsed version of an Hamiltonian term.
Parameters
- operatornp.array of strings
Block of local operators, expressed as tensor product of the local operators.
- prefactorfloat
Coupling of the term in the Hamiltonian
- maskmask
The operator is applied on a region A if the mask is true in each site of the region.
- collapse_rule(rule)[source]
Generates a collapsed version of a transition rule.
Arguments
- ruleinstance of DiscreteTransformationRule
Transition rule to be encoded in a set of collapsed rules.
Yields
List of collapsed rules encoding the applicat of the original rule to different slices of qubits.
- collapsed_state_alist of strings or None
Collapsed decsription of the state_a of the rule, encoded as a list of supergates names. If the reflection symmetry is enabled, returns None for non symmetric states.
- collapsed_state_blist of strings or None
Collapsed decsription of the state_b of the rule, encoded as a list of supergates names. If the reflection symmetry is enabled, returns None for non symmetric states.
- collapse_substate(state, position=0)[source]
Collapse a circuit or a subcircuit.
Arguments
- statematrix of strings
Description of the local (sub) circuit to be collapsed. If the number of qubits of the subcircuit is smaller than the number of qubits of the circuit, the remaining qubits are filled with “any” (identity operator) gates.
- positionint, optional
Qubit position of the subcircuit. The default is 0.
Returns
- collapsed_statelist of strings
Collapsed decsription of the state, encoded as a list of supergates names.
- decollapse_state(collapsed_state)[source]
Transform a collapsed a circuit to a non-collapsed circuit.
Arguments
- collapsed_statelist of strings
Collapsed decsription of the state, encoded as a list of supergates names.
Returns
- statematrix of strings
Description of the circuit state in terms of gates at each qubit and time-step.
- vulqano.quantummodels.collapsedquantummodel.get_collapsed_quantum_compilation_model(input_circuit, machine, qcd_instructions, shape, collapse_map)[source]
Maps the compilation problem into a quantum many-body system to simulate with qtealeaves. In this collapsed mapping, each qudit encodes a time step of the circuit.
Arguments
- input_circuitinstance of
AbstractCircuitState Classical circuit state, the initial state of the dynamics.
- machinedictionary
- hamiltonian_operatorlist of (np.array of strings, float, mask)
Abstract description of the Hamiltonian. The energy is obtained by counting how many times each subcircuit hamiltonian_operator[i][0] appears on a region A of the circuit suck that that hamiltonian_operator[i][2] is True for all (t,q) in A. The counted number is multiplied by the weight hamiltonian_operator[i][1].
- gatesset
Gates enabled on the machine (virtual gates included).
- qcd_instructionsdictionary
- annealing_Tfloat
Annealing time.
- rules_classesstr or list of ints, optional
A list of the ints identifying the rule classes that we want to generate. Default is “all” and generates all the rule classes.
- generators“std” or list of generators, optional
The list of generators producing the rules to be used. Default is “std”, in this case a standard list of rules is used.
- annealing_schedulechar, optional
Pulse schedule for the annealing process. Default is A.
- max_rules_volumeint, optional
Maximum volume allowed for the rules to be included in the driving Hamiltonian. Default is 100.
- shapetuple of ints
Shape of the lattice where the circuit is encoded, including fictitious sites added to fit in a TTN.
- collapse_mapinstance of
CollapseMap Describes how each possible time step is associated to a qudit state.
Returns
- shapetuple of ints
Shape of the lattice where the circuit is encoded, including fictitious sites added to fit in a TTN.
- my_opsinstance of
qtealeaves.operators.TNOperators Operators that transform a gate state into another gate state.
- my_obsinstance of
qtealeaves.observables.TNObservables Defines the observables of the simulation. For details, check the corresponding class.
- modelinstance of
qtealeaves.modeling.QuantumModel System Hamiltonian in the form
H = H_ext + alpha*H_initial + beta*H_driving + gamma*H_final
where:
- -H_ext = sum_i |idle><idle|
is a 1-local Hamiltonian acting on the sites of the lattice that does not correspond to a circuit site.
- -H_initial
is 1-local Hamiltonian having the initial circuit as ground state.
- -H_driving
is the Hamiltonian that drives the evolution by creating superpositions of equivalent circuit.
- -H_final
is the Hamiltonian that encodes the infidelity function.
- input_circuitinstance of