Constants

Shared constants used across SeQUeNCe.

This module centralizes immutable values that are reused by simulation and network components, including:

  • Physical constants (for example, speed of light in meters per picosecond).

  • Canonical quantum state vectors (basis states and Bell states).

  • Numerical tolerances (EPSILON) for floating-point comparisons.

  • Time unit conversion factors in picoseconds (NANOSECOND to SECOND).

  • Built-in formalism and protocol identifier strings.

sequence.constants.BARRET_KOK: Final = 'barret_kok'

Built-in Barrett-Kok generation protocol identifier.

sequence.constants.BELL_DIAGONAL_STATE_FORMALISM: Final = 'bell_diagonal'

Built-in Bell-diagonal-state formalism identifier.

sequence.constants.DENSITY_MATRIX_FORMALISM: Final = 'density_matrix'

Built-in density-matrix formalism identifier.

sequence.constants.EPSILON: Final = 1e-08

Small tolerance value for floating-point comparisons.

sequence.constants.FOCK_DENSITY_MATRIX_FORMALISM: Final = 'fock_density'

Built-in Fock density-matrix formalism identifier.

sequence.constants.KET0: Final = (1, 0)

Qubit computational basis state |0>.

sequence.constants.KET1: Final = (0, 1)

Qubit computational basis state |1>.

sequence.constants.KET_STATE_FORMALISM: Final = 'ket_vector'

Built-in ket-vector formalism identifier.

sequence.constants.MICROSECOND: Final = 1000000

Number of picoseconds in one microsecond.

sequence.constants.MILLISECOND: Final = 1000000000

Number of picoseconds in one millisecond.

sequence.constants.NANOSECOND: Final = 1000

Number of picoseconds in one nanosecond.

sequence.constants.PHI_MINUS: Final = (0.7071067811865476, 0, 0, -0.7071067811865476)

Bell state |Phi->.

sequence.constants.PHI_PLUS: Final = (0.7071067811865476, 0, 0, 0.7071067811865476)

Bell state |Phi+>.

sequence.constants.PSI_MINUS: Final = (0, 0.7071067811865476, -0.7071067811865476, 0)

Bell state |Psi->.

sequence.constants.PSI_PLUS: Final = (0, 0.7071067811865476, 0.7071067811865476, 0)

Bell state |Psi+>.

sequence.constants.SECOND: Final = 1000000000000

Number of picoseconds in one second.

sequence.constants.SINGLE_HERALDED: Final = 'single_heralded'

Built-in single-heralded generation protocol identifier.

sequence.constants.SPEED_OF_LIGHT: Final = 0.0002

Speed of light in meters per picosecond.

sequence.constants.SQRT_HALF: Final = 0.7071067811865476

Normalization factor 1/sqrt(2) used by Bell states.