Quantum Shannon Theory: Coding for Quantum Channels
Quantum Shannon theory extends Shannon’s information theory to quantum channels: compression, capacities, coding and entanglement.
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Quantum Information Theory
Entropy, channel capacity, teleportation, complexity classes and the theorems that define what quantum information can and cannot do.
155 articles
The Holevo Bound: How Much a Qubit Can Carry
The Holevo bound, proved by Alexander Holevo in 1973, limits how much classical information can be read from qubits. Its statement and consequences.
Quantum Relative Entropy as a Distinguishability Measure
Quantum relative entropy measures how distinguishable two states are and is never negative. Properties, uses and link to hypothesis testing.
Quantum Mutual Information Between Subsystems
Quantum mutual information measures total correlations between two subsystems, classical and quantum. Its definition, properties and uses.
Von Neumann Entropy and What It Counts
Von Neumann entropy extends Shannon entropy to quantum states via the density matrix. Its definition, properties and uses in quantum information.
Quantum Entropy: Measuring Uncertainty in a State
Quantum entropy measures uncertainty in a quantum state. Von Neumann entropy, its relation to classical entropy, and uses in physics and computing.
Quantum Private Information Retrieval, Explained
Quantum private information retrieval lets a user fetch data from a database without revealing which item was asked for. Protocols and limits.
Quantum Information Splitting Between Parties
Quantum information splitting distributes a quantum state among parties so that they must cooperate to recover it. Protocols and uses.
Quantum Equivalence Problems: Deciding Sameness
How to decide whether two quantum states, circuits or systems are equivalent, and the computational complexity of these problems.
Quantum Homomorphisms and Graph Structure
Quantum graph homomorphisms extend graph homomorphisms using entangled strategies in non-local games. What they reveal about graph structure.
Quantum Circuit Lower Bounds: Proving Hardness
Lower bounds for quantum circuits prove how many gates or how much depth a task needs. Methods, known results and why they matter.
Quantum Connectivity Problems on Qubit Graphs
Why qubit connectivity limits quantum computers and networks: routing, swap overhead, entanglement distribution and network topologies.
