Bell pair and GHZ-3 preparation, referencing arXiv:2607.15201

Primitive: Bell (EPR) pair preparation and three-qubit GHZ state preparation, run side by side in a single five-qubit register.

What the referenced paper says. The abstract of arXiv:2607.15201 states that entanglement detection and quantification are foundational problems in quantum information theory, and that although many sufficient conditions and entanglement measures have been proposed, efficient and direct measurement schemes for core entanglement parameters remain underdeveloped. The authors propose a set of quantum circuit schemes, based on unitary transformations and auxiliary measurements, that directly measure the bipartite concurrence and the tripartite 3-tangle. The abstract describes introducing auxiliary qubits and constructing specific controlled unitary operations so that the analytical expressions of the two measures are mapped onto measurement probabilities of the circuit output states, which the authors say enables direct quantification of bipartite and tripartite entanglement without full state tomography. Nothing beyond this abstract is restated here, and no result, number, or claim from the paper is reproduced.

What this card actually is. This card is inspired by that paper's subject matter — two-qubit and three-qubit pure entangled states — and is not an implementation of the authors' measurement circuits, nor is it endorsed by them. It builds the two canonical textbook states that such measures are usually illustrated on: a Bell pair on qubits 0 and 1 (h then cx), and a GHZ state on qubits 2, 3 and 4 (h then a cx chain). The two subsystems are prepared independently and never interact.

Provenance. The counts shown on this card come from a deterministic, seeded state-vector simulation run on Provenova (4096 shots, seed 1729). They are a simulator run, not a reproduction of any hardware experiment and not a reproduction of the paper's results. Because the two blocks are unentangled with each other, only the four bitstrings pairing a correlated Bell outcome (00 or 11) with a correlated GHZ outcome (000 or 111) carry weight, in approximately equal proportion. The circuit hash and seed on this page let anyone re-run it and obtain the identical counts.