Quantum Reality Lab Experiments & evidence

Research investigations · 5

A headline is a starting point.
Make it an investigation.

Ask a question. Make a prediction. Compare exact theory with finite samples—and see where the model stops.

Reduced-scale model · small-system teaching model

How do interacting spins respond to a sudden change?

Compare a small gate approximation with exact four-spin Hamiltonian evolution.

  1. 1Predict
  2. 2Ideal
  3. 3Ideal Shots
  4. 4Hardware
  5. 5Interpret
  6. 6Lab note
Your prediction
Open square · four interacting spins · t = 0.00
q0↑⟨Z⟩ 1.00
q1↑⟨Z⟩ 1.00
q2↑⟨Z⟩ 1.00
q3↑⟨Z⟩ 1.00

Arrows encode local ⟨Z⟩, not a complete spin state. Coupled edges: 0–1, 0–2, 1–3, 2–3.

+10−10t = 3

━ Circuit reference · ┄ Exact Hamiltonian reference

Current circuit magnetization 1.000. Neither curve is hardware data. Time is in model units, not seconds on a device.

Checking voice availability…

Exact circuit probabilities

Theoretical probabilities for the selected step and basis.

Exact numerical values
Ideal probabilities at t = 0.00
OutcomeProbability
00001.0000000
00010.0000000
00100.0000000
00110.0000000
01000.0000000
01010.0000000
01100.0000000
01110.0000000
10000.0000000
10010.0000000
10100.0000000
10110.0000000
11000.0000000
11010.0000000
11100.0000000
11110.0000000

Fixed 0–100% scale · left digit is qubit 0

Z-basis measurement probabilities. A histogram is not the complete quantum state.

What this shows

t = 0.00

A field quench drives a four-spin open square with H = −J Σ ZiZj − h Σ Xi (ℏ = 1). Ideal and Ideal Shots use the same first-order RX/RZZ product-formula circuit. The exact-Hamiltonian curve is a separate reference, so their gap is approximation error, not hardware noise.

Where this model stops

Four spins can recur and cannot establish Pasqal’s 256-spin late-time relaxation, a thermodynamic phase transition, or quantum advantage. This gate model is not Pasqal’s neutral-atom processor.

Real QPU eligibility and source paper

RX/RZZ export needs backend-target transpilation. No hardware counts have been collected for this circuit; no performance comparison with Pasqal is supported.

There is no hardware execution behind these plots. Exporting a circuit does not validate a device or create a new hardware result.

Mendes-Santos et al. · Exploring the Relaxation Landscape of a 2D Quantum Magnet ↗

Preprint · August 7, 2026; Pasqal research announcement October 27, 2026

Predict · 1 of 6

Inspect the circuit

Export the selected step and settings for Qiskit. No job is submitted.

View Qiskit code
# Quantum Reality Lab — Quench a four-spin magnet
# Reduced-scale model; not a reproduction of the cited hardware experiment.
# Source: https://arxiv.org/abs/2608.07178
# Display convention: qubit 0 is the leftmost display digit.
# Qiskit single-register count keys are reversed before display.
from qiskit import QuantumCircuit, QuantumRegister, ClassicalRegister
from math import pi

qc = QuantumCircuit(4, 4)
# Open-square edges: 01, 02, 13, 23; H=-J sum ZZ-h sum X; hbar=1
time, h, J, slices = 0, 1, 1, 8
dt = time / slices
for _ in range(slices):
    for q in range(4):
        qc.rx(-2 * h * dt, q)
    for a, b in [(0,1), (0,2), (1,3), (2,3)]:
        qc.rzz(-2 * J * dt, a, b)
qc.measure(range(qc.num_qubits), range(qc.num_clbits))

print(qc.draw())