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Research Map

The research map

The notes in this notebook are written as a web, not a syllabus: each one links to the notes it leans on, and the picture emerges from the connections. The map below is that web, drawn from the actual links between notes. Wander it freely, or, if you would rather have a guided route, follow one of the four suggested trails underneath.

Qubits: the Overview: 3 links Qubits: the Overview Reading a Fidelity Claim: 8 links Reading a Fidelity Claim The Billion-Qubit Paradox: 6 links The Billion-Qubit Paradox Fault Tolerance: 10 links Fault Tolerance The Logical Qubit: 8 links The Logical Qubit The Majorana Qubit: 5 links The Majorana Qubit The Physical Qubit: 10 links The Physical Qubit The Quantum Circuit: 4 links The Quantum Circuit Quantum Gates: 8 links Quantum Gates The Qubit: 22 links The Qubit The Random Telegraph Signal: 4 links The Random Telegraph Signal Coherence Time: 10 links Coherence Time Entanglement: 10 links Entanglement Gate Fidelity: 9 links Gate Fidelity Measurement: 12 links Measurement Quantum Error Correction: 14 links Quantum Error Correction Quantum Phase Estimation: 6 links Quantum Phase Estimation Qubit Connectivity: 8 links Qubit Connectivity Superposition: 9 links Superposition The GHZ State: 6 links The GHZ State Mermin's Inequality: 4 links Mermin's Inequality The Topological Gap Protocol: 3 links The Topological Gap Protocol Qubit Count: 9 links Qubit Count Foundations Hardware Error Correction Benchmarks circle size = number of links
The notebook as a network. Every dot is one note, sized by how many other notes link to it; every line is a real link between two notes. Hover a note to light up its connections; click it to start reading.

Prefer a guided route? Four ways in

Trail 1 · First principles

What a quantum computer actually is, built from the ground up. Start here if you are new to the field.

  1. 1.The qubit
  2. 2.Superposition
  3. 3.Measurement
  4. 4.Entanglement
  5. 5.Quantum gates
  6. 6.The quantum circuit
  7. 7.The qubit families: an overview

This trail leads to → the IonQ story, a good first article.

Trail 2 · Judging the hardware

The numbers companies advertise (qubit counts, fidelities, coherence times) and how to read them without being fooled.

  1. 1.The physical qubit
  2. 2.Coherence time
  3. 3.Gate fidelity
  4. 4.Reading a gate-fidelity claim
  5. 5.Qubit connectivity
  6. 6.Qubit count: the scoreboard that isn’t
  7. 7.The random telegraph signal

This trail leads to → the Quantinuum story, the fidelity record-holder.

Trail 3 · The road to fault tolerance

Why the useful machine needs thousands of physical qubits for every one that computes, and what that means for every roadmap.

  1. 1.Quantum error correction
  2. 2.The logical qubit
  3. 3.Fault tolerance
  4. 4.The billion-qubit paradox

This trail leads to → Week 1: networked qubits, one proposed road to scale.

Trail 4 · The contested frontier

Two live frontiers the notebook follows as they unfold: entanglement across a network, and Microsoft’s contested topological qubit.

  1. 1.The GHZ state
  2. 2.Mermin’s inequality
  3. 3.The Majorana qubit
  4. 4.The topological gap protocol

This trail leads to → Week 2: the Majorana dispute · Microsoft’s bet.

Where the trails meet the market

Every company story on the shelf, grouped by hardware approach, plus the weekly papers that track the field one publication at a time.

New notes and articles are added every week → browse all notes · browse all articles.

Prefer serendipity?

Jump into a random note →