Hope to see you in the community sync Best, Jie-Kai Chang
On 2026/02/24 16:27:11 Alisha wrote: > Hi Ryan, > > Thank you for the detailed feedback — that’s very helpful. > > I’ll start working on the POC focusing first on: > > - > > Implementing the Rust encoder with linear entanglement > - > > Reusing the IQP encoding dispatch patterns where possible > - > > Validating numerically against Qiskit on small circuits (2–4 qubits) > > I’ll open a draft PR once I have the core working end-to-end. > > Also, I’d love to join the Slack and the bi-weekly meeting — my preferred > email is: [email protected] > > Looking forward to contributing further! > > Best, > Alisha > > On Mon, Feb 23, 2026 at 5:37 AM Ryan Huang <[email protected]> wrote: > > > Hi Alisha, > > > > Thanks for the detailed write-up — this is a well-scoped proposal and > > ZZFeatureMap is a natural addition to the encoding suite. > > > > We'd love for you to go ahead and put together a POC. A few thoughts to > > guide you: > > > > API design: keeps it consistent with the rest of the codebase and plays > > better with the Rust type system. > > > > Qiskit parity: Numerical parity with Qiskit's reference implementation is > > the right goal for validation, but we don't need to mirror their API > > surface. Matching the gate-level math is what matters. > > > > Architectural note: Take a look at how the IQP encoding handles its CUDA > > kernel dispatch — the ZZ interaction pattern will have similar two-qubit > > parallelism constraints and it's worth reusing those patterns where you > > can. > > > > For the POC, I'd prioritize: > > 1. The Rust encoder + CUDA kernel with at least linear entanglement working > > end-to-end > > 2. A basic numerical comparison against Qiskit on a small circuit (2–4 > > qubits) > > 3. Python bindings can be minimal for now — just enough to run the > > validation > > > > Once the POC is up, open a draft PR against the relevant issue and we can > > give more detailed feedback from there. > > > > To engage with the community, you can join our slack channel (you can give > > me your preferred email) and join our bi-weekly community meeting at google > > meet. > > > > Looking forward to seeing you in the community meeting! > > > > Best, > > Ryan Huang > > > > On Mon, Feb 23, 2026 at 3:49 AM Alisha <[email protected]> wrote: > > > > > Hi all, > > > > > > I would like to propose implementing the ZZFeatureMap encoding for QDP > > > (GitHub issue #1008, JIRA GSOC-312). > > > > > > Background > > > ---------- > > > ZZFeatureMap is widely used in quantum machine learning frameworks such > > as > > > Qiskit for quantum kernels and variational classifiers. Adding it to QDP > > > would complete the encoding suite alongside amplitude, angle, basis, and > > > IQP > > > encodings. > > > > > > Understanding > > > ------------- > > > Each repetition layer consists of: > > > > > > 1. Applying Hadamard gates to all qubits > > > 2. Applying RZ(x_i) rotations per feature > > > 3. Applying exp(i x_i x_j Z_i Z_j) ZZ entangling interactions > > > 4. Supporting configurable entanglement patterns (full, linear, circular) > > > > > > Implementation Plan > > > ------------------- > > > > > > 1. Rust Encoder > > > - Implement QuantumEncoder trait > > > - File: qdp-core/src/gpu/encodings/zzfeaturemap.rs > > > - Parameters: num_qubits, reps, entanglement enum > > > > > > 2. CUDA Kernel > > > - File: qdp-kernels/src/zzfeaturemap.cu > > > - Parallel RZ application > > > - Efficient ZZ interaction implementation > > > - Optimized memory access for NVIDIA 30-series GPU > > > (I have access to a compatible GPU.) > > > > > > 3. Python Bindings > > > - Integrate via existing QDP API > > > - Expose reps and entanglement configuration > > > > > > 4. Testing > > > - Validate against Qiskit reference implementation > > > - Numerical tolerance comparison > > > - Unit tests for multiple entanglement modes > > > > > > I would appreciate feedback on: > > > - Preferred API design for entanglement configuration > > > - Any architectural constraints to consider before implementation > > > - Whether exact Qiskit parity is desired or QDP-style adaptation > > > > > > Looking forward to your feedback. > > > > > > Best regards, > > > Alisha Gupta > > > > > >
