I know the Solovay-Kitaev algorithm can achieve this. Is there an implementation of this or any other algorithm for the same task in Qiskit? Or perhaps some other library that interfaces well with Qiskit?
1 Answer
On the Qiskit front, a Solovay-Kitaev algorithm implementation is on its way https://github.com/Qiskit/qiskit-terra/pull/5657.
If you want to use or have a look to this LNoorl:feature/sk-pass
branch (remember is a WIP), you can install it like this:
pip install git+https://github.com/LNoorl/qiskit-terra.git@feature/sk-pass
Here is a usage example:
from qiskit.circuit import QuantumCircuit
from qiskit.circuit.library import TGate, HGate, TdgGate
from qiskit.transpiler.passes import SolovayKitaevDecomposition
circuit = QuantumCircuit(1)
circuit.rx(0.7, 0)
print('Orginal circuit:')
print(circuit)
basis_gates = [TGate(), TdgGate(), HGate()]
skd = SolovayKitaevDecomposition(recursion_degree=2, basis_gates=basis_gates, depth=5)
discretized = skd(circuit)
print('Discretized circuit:')
print(discretized)
Orginal circuit:
┌─────────┐
q_0: ┤ RX(0.7) ├
└─────────┘
Discretized circuit:
global phase: -π/8
┌───┐┌───┐┌───┐┌─────┐┌───┐┌───┐┌───┐┌───┐┌───┐┌─────┐┌───┐┌───┐┌───┐»
q_0: ┤ H ├┤ T ├┤ H ├┤ TDG ├┤ H ├┤ T ├┤ H ├┤ T ├┤ H ├┤ TDG ├┤ H ├┤ T ├┤ H ├»
└───┘└───┘└───┘└─────┘└───┘└───┘└───┘└───┘└───┘└─────┘└───┘└───┘└───┘»
« ┌─────┐┌───┐┌─────┐┌─────┐┌───┐┌───┐┌───┐┌───┐┌───┐┌───┐┌───┐┌───┐┌─────┐»
«q_0: ┤ TDG ├┤ H ├┤ TDG ├┤ TDG ├┤ H ├┤ T ├┤ H ├┤ T ├┤ T ├┤ H ├┤ T ├┤ H ├┤ TDG ├»
« └─────┘└───┘└─────┘└─────┘└───┘└───┘└───┘└───┘└───┘└───┘└───┘└───┘└─────┘»
« ┌─────┐┌───┐┌─────┐┌───┐┌───┐┌───┐┌───┐┌───┐┌───┐┌───┐┌─────┐┌───┐┌─────┐»
«q_0: ┤ TDG ├┤ H ├┤ TDG ├┤ H ├┤ T ├┤ H ├┤ T ├┤ H ├┤ T ├┤ H ├┤ TDG ├┤ H ├┤ TDG ├»
« └─────┘└───┘└─────┘└───┘└───┘└───┘└───┘└───┘└───┘└───┘└─────┘└───┘└─────┘»
« ┌─────┐┌───┐┌─────┐┌───┐┌───┐┌───┐┌───┐┌───┐┌───┐┌─────┐
«q_0: ┤ TDG ├┤ H ├┤ TDG ├┤ H ├┤ T ├┤ T ├┤ H ├┤ T ├┤ H ├┤ TDG ├
« └─────┘└───┘└─────┘└───┘└───┘└───┘└───┘└───┘└───┘└─────┘
```
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$\begingroup$ Thanks for this answer! Can I use any universal set of basis gates? $\endgroup$– shashvatApr 22, 2021 at 12:33
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1$\begingroup$ you can try any basis set, even when it is not universal. However, universal sets will work with any circuit in the universe :P $\endgroup$– lucianoApr 23, 2021 at 9:52
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$\begingroup$ It only decomposes single qubit gates though right? Line 94 here github.com/LNoorl/qiskit-terra/blob/master/qiskit/transpiler/… $\endgroup$– shashvatApr 26, 2021 at 10:53
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$\begingroup$ @luciano, I'm trying to run
skd = SolovayKitaevDecomposition(recursion_degree=2, basis_gates=basis_gates, depth=5)
but I get an error__init__() got an unexpected keyword argument 'basis_gates'
. How do I fix this? Also, it seems the location of the algorithm is now atfrom qiskit.transpiler.synthesis.solovay_kitaev
. $\endgroup$ Oct 11, 2022 at 23:17