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Gates API Reference

All gates are imported from qutritium.gates:

from qutritium.gates import H3, X01, Rx01, CSUM

Every gate inherits from qutritium.gates.Gate and provides:

  • .matrix()NDArray[np.complex128] — the unitary matrix (3×3 or 9×9)
  • .labelstr — gate name
  • .num_qutritsint — 1 or 2
  • .paramstuple[float, ...] — gate parameters (empty for fixed gates)
  • .inverse()Gate — the conjugate transpose gate
  • .is_unitary()bool — verify unitarity

Single-qutrit fixed gates

All matrices are 3×3 unitary.

Subspace Pauli-X

Gate Action Matrix
X01() \(\|0\rangle \leftrightarrow \|1\rangle\) \(\lambda_1 + \|2\rangle\langle 2\|\)
X02() \(\|0\rangle \leftrightarrow \|2\rangle\) \(\lambda_4 + \|1\rangle\langle 1\|\)
X12() \(\|1\rangle \leftrightarrow \|2\rangle\) \(\lambda_6 + \|0\rangle\langle 0\|\)

Subspace Pauli-Y

Gate Generator
Y01() \(\lambda_2 + \|2\rangle\langle 2\|\)
Y02() \(\lambda_5 + \|1\rangle\langle 1\|\)
Y12() \(\lambda_7 + \|0\rangle\langle 0\|\)

Subspace Pauli-Z

Gate Matrix
Z01() \(\mathrm{diag}(1, -1, 1)\)
Z02() \(\mathrm{diag}(1, 1, -1)\)
Z12() \(\mathrm{diag}(1, 1, -1)\)

Other fixed gates

Gate Description
I3() 3×3 identity
XPlus() Cyclic shift \(\|i\rangle \to \|i{+}1 \bmod 3\rangle\). \(X_+^3 = I\)
XMinus() Inverse cyclic shift. \((X_+)^\dagger\)
H3() Qutrit Hadamard / DFT \(F_3/\sqrt{3}\)
S3() \(\mathrm{diag}(1, 1, \omega)\). \(S^3 = I\)
T3() \(\mathrm{diag}(1, \omega^{1/3}, \omega^{-1/3})\). \(T^9 = I\)
UFT() Fourier-related gate \(U_{FT}\)

Single-qutrit parametric gates

Subspace rotations

Convention: \(R_{\text{axis},ij}(\theta) = \exp(-i\theta/2 \cdot \sigma_{\text{axis},ij})\).

Gate Parameters Subspace
Rx01(θ) 1 {\(\|0\rangle\), \(\|1\rangle\)}
Rx02(θ) 1 {\(\|0\rangle\), \(\|2\rangle\)}
Rx12(θ) 1 {\(\|1\rangle\), \(\|2\rangle\)}
Ry01(θ) 1 {\(\|0\rangle\), \(\|1\rangle\)}
Ry02(θ) 1 {\(\|0\rangle\), \(\|2\rangle\)}
Ry12(θ) 1 {\(\|1\rangle\), \(\|2\rangle\)}
Rz01(φ) 1 {\(\|0\rangle\), \(\|1\rangle\)}
Rz02(φ) 1 {\(\|0\rangle\), \(\|2\rangle\)}
Rz12(φ) 1 {\(\|1\rangle\), \(\|2\rangle\)}

Generalized rotations

\(g_{ij}(\theta, \phi) = \exp\bigl(-i\tfrac{\theta}{2}(\cos\phi\, X_{ij} + \sin\phi\, Y_{ij})\bigr)\)

Native gate in trapped-ion implementations (Ringbauer et al., Nat. Phys. 18, 1053, 2022).

Gate Parameters
G01(θ, φ) 2
G02(θ, φ) 2
G12(θ, φ) 2

Diagonal phase gate

Gate Parameters Matrix
Ud(φ₁, φ₂, φ₃) 3 \(\mathrm{diag}(e^{i\phi_1}, e^{i\phi_2}, e^{i\phi_3})\)

Two-qutrit gates

All matrices are 9×9 unitary.

Gate Action Reference
CSUM() \(\|c, t\rangle \to \|c, (t{+}c) \bmod 3\rangle\) Wang et al. (2020)
CSUMDag() \(\|c, t\rangle \to \|c, (t{-}c) \bmod 3\rangle\) CSUM inverse
CPhase() \(\|c, t\rangle \to \omega^{ct}\|c, t\rangle\) Qutrit CZ analogue
CNOT3() Legacy CNOT from v0.0.1 Equivalent to CSUM
SWAP3() \(\|a, b\rangle \to \|b, a\rangle\) Self-inverse

References

  • Bertlmann, R. A. & Krammer, P. (2008). arXiv:0806.1174 — Gell-Mann matrices \(\lambda_1\)\(\lambda_8\)
  • Ringbauer, M. et al. (2022). Nat. Phys. 18, 1053 — Generalized rotations, T3 gate
  • Wang, Y. et al. (2020). Front. Phys. 8, 589504 — CSUM, qutrit gate compilation
  • Vitanov, N. V. (2012). Phys. Rev. A 85, 032331 — SU(3) decomposition