Quantinuum Helios¶
Default Noise Model Parameters¶
Default Settings |
Helios-1E |
General |
|
Qubits (Statevector) |
32 |
Qubits (Stabilizer) |
56 |
Connectivity |
all-to-all |
Parallel 2-qubit operations |
4 |
Wasm Enabled |
True |
Physical Noise |
|
1-Qubit Fault Probability (p1) |
2.5e-05 |
2-Qubit Fault Probability (p2) |
0.0008 |
Bit-Flip Measurement Probability (0 outcome) (p_meas) |
1e-06 |
Bit-Flip Measurement Probability (1 outcome) (p_meas) |
1e-06 |
Crosstalk Measurement Fault Probability (p_crosstalk_meas) |
5.5e-05 |
Initialization Fault Probability (p_init) |
0.0005 |
Crosstalk Initialization Probability (p_crosstalk_init) |
3.5e-06 |
Ratio of 1-Qubit Spontaneous Emission to p1 (p1_emission_ratio) |
0.8 |
Ratio of 1-Qubit Spontaneous Emission in 2-Qubit Gate to p2 (p2_emission_ratio) |
0.24 |
Leakage Noise |
|
Leakage Probability per Initialization (p_prep_leak_ratio) |
0.75 |
Seepage Probability per 1-Qubit Gate (p1_seepage_prob) |
0.3333333333333333 |
Seepage Probability per 2-Qubit Gate (p2_seepage_prob) |
0.3333333333333333 |
Convert Leakage Errors to Depolarizing Errors (leak2depolar) |
False |
Dephasing Noise |
|
Quadratic Dephasing Rate (quadratic_dephasing_rate) |
0.058 |
Linear Dephasing Rate (linear_dephasing_rate) |
0.0079 |
Coherent to Incoherent Factor (coherent_to_incoherent_factor) |
1.5 |
Arbitrary Angle Noise Scaling |
|
Fit Parameter 1 (przz_a) |
1.518 |
Fit Parameter 2 (przz_b) |
0.241 |
Fit Parameter 3 (przz_c) |
1.518 |
Fit Parameter 4 (przz_d) |
0.241 |
Polynomial (przz_power) |
1.0 |
Performance¶
The performance of the Quantinuum Helios Emulator is measured in comparison to the Helios hardware. With the inclusion of an accurate and up-to-date noise model, the Helios Emulator provides a detailed representation of Quantinuum Helios output, operating on a GPU backend. Because of the memory requirements, a slowdown in the number of Hardware Quantum Credits (HQCs) processed in an hour is observed for state vector emulations using 25 qubits or more. The difference in processing time is due to the higher number of qubits combined with the realistic physical noise model of Quantinuum Helios performing a state vector emulation. It is generally recommended that users perform state vector emulations with less than 28 qubits. Though it is dependent on the submitted circuit, the execution speed of the Quantinuum Helios hardware is generally higher than the emulator with qubit counts at 28 qubits or more.
Users should be aware that Quantinuum Helios has a more complex trapping geometry than System Model H2. Additionally, this includes the new runtime component, required for real-time decisions during job execution. As a consequence, the advanced execution model on Quantinuum Helios is also supported by the Helios Emulator. In comparing the Helios emulation to Helios quantum computer results, users may experience a larger discrepancy than experienced relative to previous generations. Quantinuum Helios error models will mature over time. In the case of exceptional or unexplained variance, users should contact Quantinuum technical support at QCsupport@quantinuum.com to discuss the program and results.