Quantum Computing: A 100-Word Glossary of Key Terms and Concepts

Quantum computing is an exciting and rapidly advancing field, but the terminology can be overwhelming for those new to the subject. To help make sense of some of the core quantum concepts, I’ve compiled an alphabetical glossary of 100 essential quantum computing terms. From the qubit to quantum algorithms like Shor’s and Grover’s, this quantum dictionary covers key ideas like superposition, entanglement, quantum logic gates, and more. It explains topological quantum computing, quantum machine learning, quantum error correction, and other pivotal topics in straightforward language accessible to a general audience. Whether you’re an interested layperson or a professional seeking a quick quantum refresher, this glossary serves as a handy reference for the most important vocabulary on the road to understanding quantum computing. Read on for clear definitions of qubits, quantum parallelism, quantum supremacy, and other foundational principles powering the coming quantum revolution.

  1. Adiabatic quantum computation – Evolving Hamiltonian slowly to find ground state.
  2. Anyon – Quasiparticle with fractional statistics for topological quantum computing.
  3. Bell states – Maximally entangled two-qubit states fundamental in quantum information.
  4. Bloch Sphere – Visual representation of a qubit’s state.
  5. Boson sampling – Sampling bosons to achieve quantum advantage.
  6. Braiding – Manipulating non-abelian anyons to implement topological quantum gates.
  7. CHSH inequality – Bound on classical correlations violated by some quantum states.
  8. Continuous-variable quantum computation – Quantum computing encoding information in continuous degrees of freedom like position/momentum.
  9. Quantum advantage – Quantum computational speedup for practical applications.
  10. Quantum annealing – Optimization technique using quantum fluctuation.
  11. Quantum annealing cloud – Quantum annealer remotely accessible over cloud platform.
  12. Quantum approximate optimization algorithm – Heuristic hybrid algorithm combining quantum and classical optimization.
  13. Quantum causality – Ordering of events and prohibition on superluminal signalling imposed by quantum mechanics.
  14. Quantum coherence – Quantifying quantum superposition useful as resource.
  15. Quantum compiler – Software to map quantum algorithms onto specific hardware.
  16. Quantum computational supremacy – Outperforming classical supercomputers.
  17. Quantum contextuality – Outcome dependence on compatible measurements performed.
  18. Quantum cryptography – Encryption methods relying on principles of quantum mechanics.
  19. Quantum Darwinism – Emergence of objectivity in quantum systems through redundant environmental encoding of information.
  20. Quantum decoherence – Loss of quantum superposition due to environment.
  21. Quantum discord – Quantifying nonclassical correlations beyond entanglement.
  22. Quantum eraser – Deleting quantum interference pattern by gaining which-path information.
  23. Quantum error correction – Techniques to protect quantum information from noise.
  24. Quantum fingerprinting – Efficient quantum technique for comparing datasets.
  25. Quantum Fourier Transform – Reversible quantum form of discrete Fourier transform.
  26. Quantum gates – Fundamental quantum computational operations.
  27. Quantum key distribution – Using quantum states to securely share cryptographic keys.
  28. Quantum logic gates – Fundamental quantum computational operations.
  29. Quantum machine learning – Quantum algorithms for machine learning tasks.
  30. Quantum metrology – High precision measurement using quantum techniques.
  31. Quantum money – Cryptocurrencies using quantum physics for security.
  32. Quantum neural networks – Quantum algorithms inspired by biological neural networks.
  33. Quantum non-demolition measurement – Measuring without destroying quantum state.
  34. Quantum nonlocality – Quantum correlations not explainable by local hidden variables.
  35. Quantum optics – Field dealing with quantum states of light and their interactions.
  36. Quantum parallelism – Performing calculations on qubits in superposition.
  37. Quantum phase estimation – Estimating relative phase between quantum states.
  38. Quantum phase transition – Transition between quantum phases of matter.
  39. Quantum processor – Device for coherent quantum computation and information processing.
  40. Quantum radar – Using quantum illumination for enhanced radar capabilities.
  41. Quantum repeaters – Devices to extend range of quantum communication.
  42. Quantum retrocausality – Controversial idea of quantum influences propagating backwards in time.
  43. Quantum secure direct communication – Secure direct communication using quantum principles.
  44. Quantum simulation – Simulating quantum systems on quantum computers.
  45. Quantum spin liquid – Exotic quantum phase with fractionalized excitations.
  46. Quantum state discrimination – Determining identity of unknown quantum states.
  47. Quantum state tomography – Reconstructing unknown quantum states from measurements.
  48. Quantum steering – Nonlocal quantum correlations allowing one party to remotely steer the other’s state.
  49. Quantum supremacy – Threshold where quantum computers definitively outperform classical.
  50. Quantum teleportation – Transferring quantum states between distant qubits.
  51. Quantum thermodynamics – Extending thermodynamics to quantum regimes.
  52. Quantum tomography – Reconstructing quantum states from measurements.
  53. Quantum virtual machine – Emulation of quantum hardware on classical computer.
  54. Quantum volume – Metric of quantum processor power and scalability.
  55. Quantum walks – Quantum analogue of random walks, useful for quantum algorithms.
  56. Quantum Zeno effect – Inhibiting transitions by frequent measurement.
  57. Qubit – The basic unit of quantum information, analogous to a classical bit.
  58. Shor’s algorithm – Efficient quantum algorithm for integer factorization.
  59. Squeezed states – States with reduced quantum noise in one quadrature at the expense of increased noise in the conjugate quadrature.
  60. Stabilizer codes – Elegant technique for quantum error correction.
  61. Superdense coding – Using qubits to communicate multiple classical bits.
  62. Superconducting qubits – Qubits encoded in superconducting electrical circuits.
  63. Superposition – The ability of a qubit to exist in multiple states at once.
  64. Surface codes – Topological quantum error correcting codes.
  65. Topological quantum computation – Encoding qubits in topological properties for robustness.
  66. Trapped ion qubits – Qubits encoded in energy levels of trapped ions.
  67. Tsirelson’s bound – Maximum possible quantum violation of CHSH inequality.
  68. Variational quantum eigensolver – Hybrid algorithm to find eigenvalues of operators.
  69. Majorana zero modes – Special anyons useful as topological qubits.
  70. No-cloning theorem – Proof that unknown quantum states can’t be copied perfectly.
  71. Pauli Gates – Quantum logic gates operating on single qubits.
  72. Phase Kickback – Phenomenon where phase shifts accumulate in qubits.
  73. Photon qubits – Qubits encoded in quantum states of a photon.
  74. Quantum cloning – Producing imperfect copies of unknown quantum states.
  75. Quantum computational supremacy – Outperforming classical supercomputers.
  76. Quantum cryptography – Encryption methods relying on principles of quantum mechanics.
  77. Quantum discord – Quantifying nonclassical correlations beyond entanglement.
  78. Quantum entanglement – Nonlocal correlation between quantum systems.
  79. Quantum error correction – Techniques to protect quantum information from noise.
  80. Quantum Fourier Transform – Reversible quantum form of discrete Fourier transform.
  81. Quantum gates – Fundamental quantum computational operations.
  82. Quantum key distribution – Using quantum states to securely share cryptographic keys.
  83. Quantum logic gates – Fundamental quantum computational operations.
  84. Quantum machine learning – Field combining quantum computation and machine learning.
  85. Quantum money – Cryptocurrencies using quantum physics for security.
  86. Quantum neural networks – Quantum algorithms inspired by biological neural networks.
  87. Quantum nonlocality – Quantum correlations not explainable by local hidden variables.
  88. Quantum parallelism – Performing calculations on qubits in superposition.
  89. Quantum radar – Using quantum illumination for enhanced radar capabilities.
  90. Quantum repeaters – Devices to extend range of quantum communication.
  91. Quantum simulation – Using controllable quantum systems to simulate other less accessible ones.
  92. Quantum spin liquid – Exotic quantum phase with fractionalized excitations.
  93. Quantum state discrimination – Determining identity of unknown quantum states.
  94. Quantum state tomography – Reconstructing unknown quantum states from measurements.
  95. Quantum supremacy – Point where quantum devices outperform classical computers.
  96. Quantum teleportation – Transferring quantum states between distant qubits.
  97. Quantum thermodynamics – Extending thermodynamics to quantum regimes.
  98. Quantum volume – Metric of quantum processor power and scalability.
  99. Qubit – The basic unit of quantum information, analogous to a classical bit.
  100. Shor’s algorithm – Efficient quantum algorithm for integer factorization.