import numpy as np
from qutip.qip.circuit import QubitCircuit, Gate
from qutip.qip.compiler import GateCompiler, Instruction
__all__ = ['SpinChainCompiler']
[docs]class SpinChainCompiler(GateCompiler):
"""
Compile a :class:`.QubitCircuit` into
the pulse sequence for the processor.
Parameters
----------
N: int
The number of qubits in the system.
params: dict
A Python dictionary contains the name and the value of the parameters.
See :meth:`.SpinChain.set_up_params` for the definition.
setup: string
"linear" or "circular" for two sub-classes.
global_phase: bool
Record of the global phase change and will be returned.
pulse_dict: dict, optional
A map between the pulse label and its index in the pulse list.
If given, the compiled pulse can be identified with
``(pulse_label, coeff)``, instead of ``(pulse_index, coeff)``.
The number of key-value pairs should match the number of pulses
in the processor.
If it is empty, an integer ``pulse_index`` needs to be used
in the compiling routine saved under the attributes ``gate_compiler``.
Attributes
----------
N: int
The number of the component systems.
params: dict
A Python dictionary contains the name and the value of the parameters,
such as laser frequency, detuning etc.
pulse_dict: dict
A map between the pulse label and its index in the pulse list.
gate_compiler: dict
The Python dictionary in the form of {gate_name: decompose_function}.
It saves the decomposition scheme for each gate.
setup: string
"linear" or "circular" for two sub-classes.
global_phase: bool
Record of the global phase change and will be returned.
"""
def __init__(self, N, params, pulse_dict, setup="linear", global_phase=0.):
super(SpinChainCompiler, self).__init__(
N=N, params=params, pulse_dict=pulse_dict)
self.gate_compiler.update({
"ISWAP": self.iswap_compiler,
"SQRTISWAP": self.sqrtiswap_compiler,
"RZ": self.rz_compiler,
"RX": self.rx_compiler,
"GLOBALPHASE": self.globalphase_compiler
})
self.global_phase = global_phase
[docs] def rz_compiler(self, gate, args):
"""
Compiler for the RZ gate
"""
targets = gate.targets
g = self.params["sz"][targets[0]]
coeff = np.sign(gate.arg_value) * g
tlist = abs(gate.arg_value) / (2 * g)
pulse_info = [("sz" + str(targets[0]), coeff)]
return [Instruction(gate, tlist, pulse_info)]
[docs] def rx_compiler(self, gate, args):
"""
Compiler for the RX gate
"""
targets = gate.targets
g = self.params["sx"][targets[0]]
coeff = np.sign(gate.arg_value) * g
tlist = abs(gate.arg_value) / (2 * g)
pulse_info = [("sx" + str(targets[0]), coeff)]
return [Instruction(gate, tlist, pulse_info)]
[docs] def iswap_compiler(self, gate, args):
"""
Compiler for the ISWAP gate
"""
targets = gate.targets
q1, q2 = min(targets), max(targets)
g = self.params["sxsy"][q1]
coeff = -g
tlist = np.pi / (4 * g)
if self.N != 2 and q1 == 0 and q2 == self.N - 1:
pulse_name = "g" + str(q2)
else:
pulse_name = "g" + str(q1)
pulse_info = [(pulse_name, coeff)]
return [Instruction(gate, tlist, pulse_info)]
[docs] def sqrtiswap_compiler(self, gate, args):
"""
Compiler for the SQRTISWAP gate
"""
targets = gate.targets
q1, q2 = min(targets), max(targets)
g = self.params["sxsy"][q1]
coeff = -g
tlist = np.pi / (8 * g)
if self.N != 2 and q1 == 0 and q2 == self.N - 1:
pulse_name = "g" + str(q2)
else:
pulse_name = "g" + str(q1)
pulse_info = [(pulse_name, coeff)]
return [Instruction(gate, tlist, pulse_info)]
[docs] def globalphase_compiler(self, gate, args):
"""
Compiler for the GLOBALPHASE gate
"""
self.global_phase += gate.arg_value