DualYbSim

Noise channel reference

Every channel in this library is named after the corresponding channel in the noise-model appendix of the dual-Yb surface-code paper. This page is the mapping between the paper’s notation and the Python identifiers.

Naming convention

Paper notation	Identifier	Example
subscript	joined with `_`	`LOSS_g`, `ZERR_gm`, `DECAY_rg`
superscript `(...)`	appended with `_`	`LOSS_g^(meas)` → `LOSS_g_meas`, `DECAY_mg^(gate)` → `DECAY_mg_gate`
probability `p_n^(x)`	`p_n_x`	`p_1^(gm)` → `p_1_gm`, `p_2^(dual)` → `p_2_dual`
transition probability `p_(a→b)^(x)`	`p_a_b_x`	`p_(g→L)^(meas)` → `p_g_L_meas`
rate `Γ_ab`	`gamma_ab`	`Γ_rg` → `gamma_rg`, `Γ_gL` → `gamma_gL`
time `T_n^(x)`, `t_x`	`T_n_x`, `t_x`	`T_2^(gm)` → `T_2_gm`, `t_1Q^(c)` → `t_1Q_c`

Channel names appear as keys of the noise_channels dict on each Kraus class in dualybsim.kraus.yb171 / dualybsim.kraus.yb174, and as the channel argument of YbNoiseChannel.get_kraus_operators and CPTP.

Channels by category

The paper groups channels into six categories. Loss and decay channels are realised in Stim as HERALDED_ERASE; Pauli channels as PAULI_CHANNEL_1, DEPOLARIZE1, DEPOLARIZE2, X_ERROR or Z_ERROR.

Coherent-control

Channel	Isotope	Meaning
`DEP1_c`	174	single-qubit depolarising error on the clock transition
`DEP1_g`	171	single-qubit depolarising error inside the ground manifold
`DEP1_m`	171	single-qubit depolarising error inside the metastable manifold
`DEP1_gm`	171	depolarising error during clock-transition excitation
`DECAY_mg_gate`	171	metastable→ground damping driven by the nuclear-spin control laser
`DEP2_c`	174	two-qubit depolarising error, clock–clock
`DEP2_m`	171	two-qubit depolarising error, m–m
`DEP2_dual`	171, 174	two-qubit depolarising error, 171-m with 174-clock

Measurement

Channel	Isotope	Meaning
`LOSS_g_meas`	171, 174	atom loss from the ground manifold during fluorescence imaging
`FLIP_g`	171	in-manifold bit flip induced by the imaging lasers
`MERR`	171, 174	classical discrimination error of the loss-aware readout

Reset

Channel	Isotope	Meaning
`LOSS_g_reset`	171, 174	loss from the ground manifold during preparation or motional reset
`LOSS_m_reset`	171	loss from the metastable manifold during spin reset
`FLIP_g`	171	nuclear-spin flip in the ground manifold during reset
`FLIP_m`	171	nuclear-spin flip in the metastable manifold during reset

Idling

Probabilities follow p(t) = 1 − exp(−t/T).

Channel	Isotope	Timescale
`ZERR_c`	174	`T_2^(c)`
`ZERR_g`	171	`T_2^(g)`
`ZERR_m`	171	`T_2^(m)`
`ZERR_gm`	171	`T_2^(gm)`, clock-transition coherence. Available in the Kraus layer but not injected into circuits — see `parameter_reference.md`
`XERR_g`	171	`T_1^(g)`
`XERR_m`	171	`T_1^(m)`

Decay

Probabilities follow p(t) = 1 − exp(−Γt). The Rydberg branches share a total rate Γ_Ryd split 0.51 / 0.42 / 0.07 into LOSS_r / DECAY_rg / DECAY_rm.

Channel	Isotope	Rate
`LOSS_r`	171, 174	`Γ_rL`, Rydberg decay to untrapped or dark states
`DECAY_rg`	171, 174	`Γ_rg`, Rydberg decay to the ground manifold
`DECAY_rm`	171, 174	`Γ_rm`, Rydberg decay to the metastable manifold
`DECAY_mg`	171, 174	`Γ_mg`, metastable→ground decay
`LOSS_g`	171, 174	`Γ_gL`, ground-manifold loss from the finite trap lifetime
`LOSS_m`	171, 174	`Γ_mL`, metastable-manifold loss from the finite trap lifetime

Transportation

Channel	Isotope	Meaning
`LOSS_g_hand`	171, 174	ground-manifold loss during trap handover
`LOSS_m_hand`	171, 174	metastable-manifold loss during trap handover

Which channels each Kraus class provides

Class	Channels
`Kraus1Q_174`	`DEP1_c`, `ZERR_c`, `LOSS_g`, `LOSS_m`, `DECAY_mg`, `LOSS_r`, `DECAY_rg`, `DECAY_rm`
`Kraus2Q_174174`	`DEP2_c`, `ZERR_c`, `LOSS_g`, `LOSS_m`, `DECAY_mg`, `LOSS_r`, `DECAY_rg`, `DECAY_rm`
`KrausRESET_174`	`LOSS_g_reset`
`KrausMEASURE_DISC_174`	`MERR`
`KrausMEASURE_174`	`LOSS_g_meas`, `LOSS_m`, `DECAY_mg`, `LOSS_r`, `DECAY_rg`, `DECAY_rm`
`Kraus1QClock_171m`	`DEP1_gm`, `LOSS_g`, `LOSS_m`, `DECAY_mg`, `LOSS_r`, `DECAY_rg`, `DECAY_rm`
`Kraus1Q_171m`	`DEP1_m`, `DECAY_mg_gate`, `ZERR_g`, `XERR_g`, `ZERR_m`, `XERR_m`, `ZERR_gm`, `LOSS_g`, `LOSS_m`, `DECAY_mg`, `LOSS_r`, `DECAY_rg`, `DECAY_rm`
`Kraus2Q_171m171m`	`DEP2_m`, `ZERR_g`, `XERR_g`, `ZERR_m`, `XERR_m`, `ZERR_gm`, `LOSS_g`, `LOSS_m`, `DECAY_mg`, `LOSS_r`, `DECAY_rg`, `DECAY_rm`
`KrausRESET_171m`	`LOSS_m_reset`, `FLIP_m`
`KrausMEASURE_DISC_171m`	`MERR`
`KrausMEASURE_171m`	`FLIP_g`, `LOSS_g_meas`, `ZERR_m`, `XERR_m`, `ZERR_gm`, `LOSS_m`, `DECAY_mg`, `LOSS_r`, `DECAY_rg`, `DECAY_rm`

Mapping from the legacy channel names

For anyone cross-reading against results produced before this library existed. The paper’s conventions section explicitly avoids leakage as a way of classifying errors, which is why every *LEAK name became either LOSS_* or DECAY_*.

Legacy name	Here
`GLEAK`	`LOSS_g`
`MLEAK`	`LOSS_m`
`MGLEAK`	`DECAY_mg`
`MGLEAK_gate`	`DECAY_mg_gate`
`RLEAK`	`LOSS_r`
`RGLEAK`	`DECAY_rg`
`RMLEAK`	`DECAY_rm`
`GZERR`	`ZERR_g`
`MZERR`	`ZERR_m`
`GMZERR`	`ZERR_gm`
`GXERR` (T1 idling)	`XERR_g`
`MXERR` (T1 idling)	`XERR_m`
`GXERR_read`	`FLIP_g`
`MXERR_prep`	`FLIP_m`
`GLOSS_prep`	`LOSS_g_reset`
`MLOSS_prep`	`LOSS_m_reset`
`GLOSS_meas`, `GLOSS_read`	`LOSS_g_meas`
`DEP1_gm` (174 class)	`DEP1_c`
`DEP2_gm` (174 class)	`DEP2_c`
`ZERR_gm` (174 class)	`ZERR_c`
`XERR_mr`	removed — no such channel in the paper, and the legacy default was 0

Three legacy keys were ambiguous because the same string named different physical channels in different classes; the paper names disambiguate them:

MXERR was the T_1^(m) idling channel in Kraus1Q_171m but the reset spin flip in KrausRESET_171m → now XERR_m and FLIP_m.
GXERR was the T_1^(g) idling channel but the imaging bit flip in KrausMEASURE_171m → now XERR_g and FLIP_g.
GLOSS was the reset loss in KrausRESET_174 but the readout loss in KrausMEASURE_174 / KrausMEASURE_171m → now LOSS_g_reset and LOSS_g_meas.

The twirled measurement helpers on NoiseModelParameters return the loss probability under the key p_loss (legacy: p_leak), matching the paper’s E_loss channel.

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