Journal

Tag: superposition

Long-form notes, Qiskit experiments, and applied optimization thinking.

One Electron Does Not Necessarily Mean One Definite Position

A key conceptual obstacle in understanding coherence is the assumption that because there is only one electron, it must always occupy one definite position and follow one definite path. Quantum mechanics separates these ideas: there can be one electron while its quantum state does not assign it one definite position before measurement.

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One Electron, Two Paths: From Interference to Which-Path Measurement

The double-slit experiment becomes genuinely quantum when electrons are sent one at a time. A spread of detector hits alone does not prove wave behavior; the crucial evidence is interference between probability amplitudes associated with alternative paths. This note follows the questions of what interferes, where negative phase comes from, whether one electron involves both paths, and what happens when we measure which slit it passes through.

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Why Single-Electron Experiments Reveal Wave-Like Interference

A spread of electron impacts does not by itself demonstrate wave behavior. The important observation is that opening two possible paths produces a probability distribution that is not simply the sum of the distributions from each path separately. This note follows the learner's questions from localized electron detections to the real meaning of quantum interference.

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Where Did the Qubit Superposition Equation Come From?

The familiar qubit equation |ψ⟩ = α|0⟩ + β|1⟩ was not invented as a standalone formula by one person. This note follows the question of where it came from, connecting classical wave superposition, Schrödinger's linear wave mechanics, Dirac's abstract state notation, and the later language of qubits.

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