CHANGELOG

Table of Contents

• v0.9.0
• v0.8.0
• v0.7.0
• v0.6.0
• v0.5.0
• v0.4.0
• v0.3.1
• v0.2.1
• v0.1.1
• v0.1.0

---

v0.9.0

• add Quantum Approximate Optimization Algorithm
  • add Why QAOA?
  • add QAOA Ingredients
  • add Structure of the QAOA Ansatz
  • add Unitaries from Hamiltonians
  • add Cost Hamiltonian and Cost Operator
  • add Mixer Hamiltonian and Mixer Operator
  • add Alternating Operators and p Layers
  • add QUBO Problems for QAOA
  • add From QUBO to Cost Hamiltonian
  • add Practical QAOA Circuit Construction

---

v0.8.0

• add Variational Quantum Algorithms (VQAs)
  • add Why Variational Algorithms?
  • add General Structure of a VQA
    • add Variational Quantum Algorithms
    • add Parametric Quantum Circuits (Ansätze)
    • add Classical Optimizer
    • add Iterative Optimization Loop
  • add Building Blocks of Variational Algorithms
    • add Cost Function
    • add Ansatz Design
    • add Optimizer Choice
    • add Hardware Efficient Ansatz
  • add Advantages and Limitations
    • add Strengths of Variational Algorithms
    • add Weaknesses of Variational Algorithms
    • add Barren Plateaus
    • add Why Variational Algorithms Matter
  • add Variational Quantum Eigensolver (VQE)
    • add The Physical Motivation
    • add Hamiltonians and Molecular Energy
    • add Variational Principle
    • add VQE Objective Function

---

v0.7.0

• add QUBO Formulation
  • add QUBO Problems
    • add Introduction to QUBO
    • add QUBO as an Energy Minimization Problem
    • add Boolean Logic in QUBO
  • add Continuous Variables and Constraints
    • add Continuous Variables through Binary Expansion
    • add Constraints in QUBO
    • add Penalty Terms
    • add Penalty Coefficients
    • add Equality Constraints in QUBO
  • add From QUBO to Quantum Systems
    • add Hamiltonian Recap
    • add The Eigenspectrum
    • add Why Map QUBO to Quantum Mechanics?
    • add Encoding Bit Strings into Quantum States
    • add Constructing the QUBO Hamiltonian
  • add The Ising Model
    • add QUBO, Hamiltonian, and Ising: Taxonomy
    • add Classical Ising Model
    • add Quantum Ising Model
  • add Quantum Annealing
    • add Annealing Hamiltonian
    • add Evolution of the Eigenspectrum
  • add Summary

---

v0.6.0

• add Transpiling
  • add Quantum Fidelity
    • add Why Quantum Computers Are Noisy
    • add Gate Infidelity
    • add Decoherence
      • add Phase-Flip Errors
      • add Bit-Flip Errors
      • add Generic Errors
    • add Fidelity of a Quantum Gate
    • add Fidelity and Decoherence
  • add Quantum Error Correction
    • add Quantum Computation Errors
    • add Quantum Error Correction Codes (QECC)
    • add Logical Gates
  • add Quantum Transpiling
    • add The Quantum Computing Stack
    • add Placement
    • add Scheduling
    • add Routing

---

v0.5.0

• add Limits of Quantum Information
  • add No-Cloning Principle
    • add Why Cloning Matters
    • add Formal Statement
  • add No-Deleting Principle
  • add No-Signaling Principle
  • add EPR Paradox and Quantum Correlation
    • add Definition of EPR Paradox
    • add Entanglement and Quantum Correlation
    • add Classical vs Quantum Correlation
    • add Entanglement vs Quantum Correlation

---

v0.4.0

• refactor: rename complex-numbers-recap to complex-numbers and add more content
• refactor: Dirac’s notation section for clarity and readability
• refactor: add Pauli Gates section (X, Y, Z)
• feat: add Bloch sphere diagrams for Pauli-X and Pauli-Z eigenstates on the Bloch sphere
• feat: enhance Pauli-Y gate section with detailed explanations and visualizations
• feat: enhance Hadamard gate section with detailed explanations and visualizations
• add Single Qubit States
  • add Building and Measuring Qubits (Intuition)
  • add From Polarization to Qubits
  • add Single Qubit Measurement
  • add Superposition
  • add Information Carried by a Single Qubit
  • add State Space of a Single-Qubit System
• refactor: Multiple Qubit States section and divide it into:
  • Tensor Product
  • Building a Two-Qubit System
  • Separable vs Entangled States
  • Why Entanglement Matters
  • Exercise: Normalization of Tensor Product States
• add the following sections to Multiple Qubit Gates:
  • refactor Introduction to Multiple Qubit Gates
  • add Parallel Gates
  • add Hadamard Transform on Multiple Qubits
• refactor multi qubit gates into Main Multi-Qubit Gates section, with the following structure:
  • add Controlled NOT (CNOT) Gate
  • add Generic Controlled Gate (CU)
  • add SWAP Gate
  • add Controlled-Controlled NOT (CCNOT) Gate (Toffoli)
• refactor: remove Foundations of Universal Quantum Circuits section in favor of Quantum Circuit Representation section
• refactor: enhance Entanglement section with more detailed explanations and visualizations
• add Projection Operator topic in Measurement section
• add Observables and Measurements in Multiple Qubit Gates
  • add Observables: What Are We Measuring?
  • add Measurement Operators and Projectors
  • add Expectation Value
  • add Measuring |+> with the Pauli-Z Observable
  • add Recovering Probabilities from Expectation Values
• refactor: remove useless Measurement in Multi-Qubit Systems section
• add Heisenberg Representation of Quantum Circuits section
• add Clifford Gates subsection in Multiple Qubit Gates
• add Universal Set of Quantum Gates subsection in Multiple Qubit Gates
• add Fault-Tolerant Quantum Gates subsection in Multiple Qubit Gates
  • add Logical vs Physical Qubits
  • add Transversal Gates
  • add Why Non-Clifford Gates Are Difficult
  • add Physical vs Logical Gate Sets

---

v0.3.1

• add Multiple Qubit Gates
  • add Multiple Qubit States
  • add Introduction to Multiple Qubit Gates
  • add Tensor Product of Quantum Gates
  • add Controlled NOT (CNOT) Gate
  • add Generic Controlled Gate
  • add SWAP Gate
  • add Toffoli Gate (CCNOT)
  • add Foundations of Universal Quantum Circuits
  • add Entanglement
  • add Measurement in Multi-Qubit Systems
  • add Limits of Quantum Information
    • add No-Cloning Principle
    • add No-Deleting Principle
    • add No-Signaling Principle

---

v0.2.1

• add Single Qubit Gates
  • add Operations on Qubits
  • add Quantum Logic Gates Overview
  • add Main Single-Qubit Gates
    • add Identity Gate (I)
    • add Pauli-X (NOT) Gate
    • add Pauli-Z (Phase Flip) Gate
    • add Pauli-Y Gate
    • add Phase Gate (S)
    • add Hadamard Gate (H)
  • add Properties
  • add When Does a Gate Create Superposition?
  • add Single-Qubit Quantum Circuits
  • add Outer Product of Kets
  • add Measurement

---

v0.1.1

• add constraints when a qubit is on a superposition, on page 12, subsection Single Qubits

---

v0.1.0

• add CHANGELOG.md and README.md
• add Introduction
  • add Complex Numbers recap
  • add Dirac's Notation
  • add Single Qubits