Noise simulation: Pauli channels, amplitude damping and readout error

未关闭
  • 哪里不对？
#8 0 条评论 0 个 reaction 已指派 0 人 在 GitHub 查看

还没有人认领这个 Issue。

评估

难度
4/5
预计耗时
3-5 天
新手友好度
55/100
Issue 类型
功能
描述清晰度
描述清楚
活跃度
活跃
技术栈
python, rust
领域
backend

调研方向

Start with the per-shot dynamic branch in src/circuit.rs and the measurement and renormalisation pattern in src/backend.rs; trace how apply_gate_kernel and probability_of_one are used. Implementing this spans gate execution, noise sampling, and fast-path behavior. Done means run supports the listed noise channels and the state inspection methods reject gate noise as specified.

由索引模型根据 Issue 内容生成。

描述

enhancement
What you want to do
Summary

Every result today comes from an ideal, noiseless device. Studying error mitigation, error correction or how an algorithm holds up on real hardware needs gate noise and readout error. Right now users have to switch to another simulator for that.

Implementation notes
  • Use quantum trajectories (Monte Carlo wavefunction). The path that simulates each shot separately
    (QuantumCircuit::run, dynamic branch in src/circuit.rs) already does what this needs: one state
    per shot, a random generator, and measure_qubit / reset_qubit.
  • Pauli channels: after a gate, draw a random Pauli with the channel's probabilities and apply it with
    apply_gate_kernel. Single-qubit gate fusion has to stop at every noise point, or fuse only
    between noise points.
  • Amplitude damping is not a mixture of unitaries. Its Kraus branch probabilities depend on the state,
    p(jump) = γ · P(qubit = 1), and probability_of_one already computes that. Then apply the
    non-unitary 2×2 matrix and renormalise, the same pattern as measure_qubit in src/backend.rs.
  • Readout error only flips classical bits after sampling, so circuits that only measure at the end
    keep the fast path when readout is their only noise.
  • statevector(), probabilities() and expectation() should raise when given gate noise,
    since the state is a mixture. A density-matrix backend could be a later issue.
What it could look like
noise = qsengine.NoiseModel(
    depolarizing=1e-3,        # after every single-qubit gate
    depolarizing_2q=1e-2,     # after every controlled gate, on each qubit it touches
    amplitude_damping=5e-4,   # T1-style decay after every gate
    readout=0.02,             # chance each measured bit is flipped
)
counts = qc.run(shots=4000, seed=1, noise=noise)
Contributing
  • I would like to open a pull request for this (see CONTRIBUTING.md).
主要语言
Rust
星标
1
派生
0
平均合并
12 分钟
30 天内合并 PR
4

环境准备

  • 没有 Dockerfile 或 Docker Compose 文件
  • 没有 Pull Request 模板
  • 阅读贡献指南

从这里开始

  1. 先读完整个 Issue，再读项目的贡献指南。
  2. 在 Issue 下留言说明你要接手 —— 这能避免两个人做同样的事。
  3. Fork 仓库，在一个分支上完成修改。
  4. 提交 Pull Request，并在描述里引用这个 Issue 编号。

kaiwave/qsengine 的其他 Issue

查看 kaiwave/qsengine 的全部 Issue

相似的 Issue

更多 Rust Issue

把新 issue 发到你的邮箱

精选适合新手参与的 GitHub issue 摘要。