
From Noisy Qubits to Fault-Tolerant Quantum Computers
The big-picture architecture: noisy physical qubits, error-corrected logical qubits, fault-tolerant machines, and how industry roadmaps map onto all three.
A complete learning path in 11 stages: quantum fundamentals, how quantum computers work, hardware, programming, algorithms, quantum and AI, applications, security, post-quantum cryptography, networking, and the future of quantum computing.
19 posts

The big-picture architecture: noisy physical qubits, error-corrected logical qubits, fault-tolerant machines, and how industry roadmaps map onto all three.

Not quantum vs classical: how CPUs, GPUs, NPUs and QPUs each do what they're best at, and how quantum-centric, hybrid computing will actually run.

ML-KEM, ML-DSA and SLH-DSA explained, how hybrid TLS already protects your browser, what changes for PKI, and a practical plan to start migrating now.

How Grover, Shor, the Quantum Fourier Transform, variational algorithms, quantum simulation and optimisation work, and where quantum advantage really comes from.

What AI already does for quantum computers, what quantum might one day do for AI, and why a QPU is not a drop-in replacement for the GPUs that train AI.

Post-quantum certificates, ML-DSA signatures, hybrid certificates, TLS, crypto agility and lifecycle, with a working quantum-safe CA lab and a migration plan.

Chemistry, materials, drug discovery, energy, optimisation and science: which real problems quantum computers could help with, and how strong each case is.

Quantum computing isn't the next AI. Hardware, algorithms, investment and error correction are converging, and AI and quantum now feed each other.

How RSA, ECC, TLS, certificates, PKI and digital signatures work, why Shor's algorithm could break them, and why it's a future threat you plan for today.

CPU, GPU and QPU compared on bits, gates, memory, measurement, algorithms and errors, and why we can't simply replace CPUs with quantum processors.

Superconducting circuits, trapped ions, neutral atoms, photons, silicon spins and topological qubits compared: how each works, who builds it, and the trade-offs.

Follow one quantum circuit through the real machine: compiler, control electronics, cryostat, qubits, gates, readout, errors, shots and post-processing.

How many imperfect physical qubits become one reliable logical qubit: the surface code, code distance, the threshold, decoding, and why raw qubit counts mislead.

X, Y, Z, Hadamard, CNOT, rotation gates and measurement explained with a real circuit diagram, Qiskit code and tested results for every gate.

A concept-building guide to the three ideas behind every quantum computer: state probabilities, correlations no classical bits can copy, and measurement.

Noise, decoherence, gate errors, measurement errors, crosstalk and environmental interference explained, plus how quantum error correction makes qubits reliable.

The inside of a quantum computer is about 270 times colder than outer space. Here's why heat destroys qubits, and why the machine looks like a giant chandelier.

A hands-on lab: install Qiskit, create a qubit, apply a Hadamard gate, measure it and run it, first on a simulator, then on a real IBM quantum computer.

Qubits, superposition, measurement, entanglement, gates and circuits explained from zero with a coin analogy, plus a first circuit you can run in your browser.