Vol. 0.2 Edition 2026 MIT License Open source

Quantum circuits for electron microscopy.

QuScope rebuilds transmission electron microscopy image formation as quantum circuits. The electron wavefunction is amplitude-encoded on qubits, and every optical element (specimen phase grating, Fresnel propagation, objective lens) is a diagonal unitary between quantum Fourier transforms, validated against classical references.

★ Simulated ★
with QuScope
4pipelines Matches the
classical model
Quantum-circuit simulation of a phase-contrast CTEM image of a crystalline specimen, computed with QuScope: a lattice of dark atomic-column contrast in grey speckle
Fig. 01 — QuScope CTEMarXiv:2602.13438

The method

The microscope, rewritten as a circuit.

One circuit per image (CTEM) or per probe position (STEM); slices repeat for thick specimens.

01 //Encoding

Wavefunction on qubits

An N×N wavefield lives on 2 log2N qubits through amplitude encoding.

02 //Circuits

Optics as diagonal gates

Phase gratings, Fresnel propagation and the lens are diagonal unitaries between quantum Fourier transforms.

03 //Verified

Validated

Noise-free circuits reproduce the classical reference implementations to unit fidelity.

04 //Backends

Simulator to hardware

Qiskit Aer statevector and shots, noise models, and IBM Quantum devices through one backend manager.

From column to circuit

Every lens has a gate.

The CTEM column, stage by stage: the classical image-formation model and its quantum-circuit counterpart. Hover or tap a stage to find it in the column (after Lam & dos Reis, arXiv:2602.13438, Fig. 1).

Schematic CTEM column: electron source, condenser lenses, specimen, objective lens and detector Source Condenser 1 Specimen 2 Objective 3 Detector 4
Conventional TEM column
  1. Stage 01

    Illumination

    Classical CTEM model

    Incident wave

    ψ(r)=φ(r⊥,z)exp(ik0z)
    Quantum circuit

    State preparation

    |ψ0⟩=H⊗n|0⟩⊗n
  2. Stage 02

    Specimen

    Classical CTEM model

    Phase grating

    t(r⊥)=exp[iσVproj(r⊥)] φexit(r⊥)=t(r⊥)φinc(r⊥)
    Quantum circuit

    Diagonal phase operation

    Uobj=∑i,jeiσVij|i,j⟩⟨i,j|
  3. Stage 03

    Propagation & objective lens

    Classical CTEM model

    Free space + lens in Fourier space

    φ~(k⊥,z)=φ~(k⊥,0)exp[−iπλzk⊥2] H(k⊥)=exp[−iχ(k⊥)],CTF(k)=sin[χ(k)]
    Quantum circuit

    QFT to momentum space + diagonal phases

    UQFTUP(z)Uχ

    All unitary gates.

  4. Stage 04

    Detection

    Classical CTEM model

    Image intensity

    |φimg|2
    Quantum circuit

    Inverse QFT and measurement

    |ψimg⟩=UQFT†UχUP(z)UQFTUobj|ψ0⟩

The catalogue

Four validated imaging pipelines.

Pick a pipeline; the plate highlights the gates it uses.

Side A · Track 1

CTEM (weak phase object)

  • Phase grating eiσV applied to the encoded plane wave.
  • QFT, the contrast transfer function of the objective lens, inverse QFT.
  • Bright-field image from the measured register.
quantum_ctem_circuit
Experimental: CBED · next release Frozen phonons · TDS · next release Bloch-wave QPE · later
Plate II — The circuit2 log₂N qubits

Each box is one diagonal gate or Fourier transform.

The idea, in one sentence

Every optical element of the microscope becomes a diagonal unitary between two quantum Fourier transforms.

The QuScope approach
Lam & dos Reis · arXiv 2026

The family

One project — several techniques.

QuScope aims to simulate the range of TEM techniques with quantum algorithms: imaging in the core package, ptychography and EELS in sister modules.

Corev0.2.1

QuScopeQuantum-circuit TEM simulation

CTEM, STEM and multislice imaging as quantum circuits, with a 5th-order lens model, Kirkland potentials, materials workflows and Aer or IBM Quantum backends.

Sister moduleIn preparation

ptyqoQuantum algorithms for electron ptychography · said “ptycho”

Dose limits of electron ptychography for beam-sensitive specimens: STEM probe and multislice circuits validated against abTEM, electron counting, quantum and classical Fisher information and thermal vibrations, with gas and liquid cells as the demanding in-situ test cases.

PlaceholderComing soon

qeelsQuantum EELS

Quantum algorithms for electron energy-loss spectroscopy, the next technique in the family.

Related

q-matsuiteMaterials data, ready for quantum simulation

Open-source tools linking materials databases to fault-tolerant quantum algorithms, starting with QMatBridge.

The lab

dos Reis LabMaterials Science · Northwestern

Roberto dos Reis's materials science lab at Northwestern University, home of the QuScope project.

In print

The papers.

Preprints on arXiv, quantum physics with materials-science cross-lists.

Admit one · Get started

Install QuScope in one line.

pip install quscope

Latest fixes (0.2.1): git clone -b v0.2.x https://github.com/QuScope/QuScope

from quscope.quantum_ctem import QuantumCTEMCircuit, QuantumCTEMParameters
import numpy as np

params = QuantumCTEMParameters(acceleration_voltage=200e3, grid_size=8,
                               pixel_size=0.5, defocus=-659.7, cs=1.3)
result = QuantumCTEMCircuit(params).simulate(np.random.rand(8, 8) * 100)
print(result["intensity"].shape)   # (8, 8)

Ticket No.

0.2.1

★ Star on GitHub Read the docs

Valid on Python 3.9+

Cite

@article{lam2026quscope,
  title   = {QuScope: An Open-Source Python Framework for Quantum-Circuit
             Simulation of Transmission Electron Microscopy},
  author  = {Lam, Sean D. and dos Reis, Roberto},
  journal = {arXiv preprint arXiv:2608.02782},
  year    = {2026}
}

@article{lam2026quantum,
  title   = {Quantum Algorithm Framework for Phase-Contrast Transmission
             Electron Microscopy Image Simulation},
  author  = {Lam, Sean D. and dos Reis, Roberto},
  journal = {arXiv preprint arXiv:2602.13438},
  year    = {2026}
}

Open source · MIT

How to contribute.

QuScope is built in the open. Bug reports, tests, docs and new TEM techniques as circuits are all welcome.

01 //Report

Report a bug

Found a result that disagrees with your classical reference? Open an issue with a minimal script and the versions you ran.

Open an issue →

02 //Code

Submit code

Fix a bug, tighten a circuit, or bring another TEM technique to quantum algorithms. Pull requests go to main.

Pull requests →

03 //Docs

Docs and tests

Clearer docstrings, validation against abTEM or py4DSTEM, and edge-case tests are among the most useful contributions.

Contributor guide →

04 //Examples

Share an example

Notebooks and applications live in a separate repository, so the core package stays lean.

examples-applications →

Your first pull request

# fork QuScope on GitHub, then:
git clone https://github.com/<you>/QuScope.git && cd QuScope
python -m venv quscope_dev && source quscope_dev/bin/activate
pip install -e ".[dev,docs]"
git checkout -b feature/my-change
pytest tests/                     # keep the suite green
# commit, push, then open a pull request against main

Style: Black and isort, Google-style docstrings, tests for new functionality. Full details in the contributor guide.