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Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Picturing Quantum Processes Aleks Kissinger QTFT, V axj o 2015 June 10, 2015 Introduction 1. Linear maps 2. Quantum maps 3. Consequences


  1. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Picturing Quantum Processes Aleks Kissinger QTFT, V¨ axj¨ o 2015 June 10, 2015

  2. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Quantum Picturalism: what it is , what it isn’t • ‘QPism’ ☺ is a methodology for expressing , teaching , and reasoning about quantum processes

  3. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Quantum Picturalism: what it is , what it isn’t • ‘QPism’ ☺ is a methodology for expressing , teaching , and reasoning about quantum processes • Diagrams live at the centre, thus composition and interaction

  4. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Quantum Picturalism: what it is , what it isn’t • ‘QPism’ ☺ is a methodology for expressing , teaching , and reasoning about quantum processes • Diagrams live at the centre, thus composition and interaction • QP is not a reconstruction , but some ideas from operational reconstructions play a major role, e.g. ρ ′ ρ ρ ′ = Φ Φ � f µ ρ purification local/process tomography

  5. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Quantum Picturalism: what it is , what it isn’t • ‘QPism’ ☺ is a methodology for expressing , teaching , and reasoning about quantum processes • Diagrams live at the centre, thus composition and interaction • QP is not a reconstruction , but some ideas from operational reconstructions play a major role, e.g. ρ ′ ρ ρ ′ = Φ Φ � f µ ρ purification local/process tomography • ...and relationship between operational setups and theoretical models : � � � � � U � � � � = � � � � � � � � � U � � ρ

  6. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Picturing Quantum Processes A first course in quantum theory and diagrammatic reasoning Bob Coecke & Aleks Kissinger CUP 2015

  7. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Outline Picturing Quantum Processes chapters 4-9 (roughly)

  8. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Outline Picturing Quantum Processes chapters 4-9 (roughly) 1. Process theory of linear maps

  9. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Outline Picturing Quantum Processes chapters 4-9 (roughly) 1. Process theory of linear maps 2. quantum maps via ‘doubling’ construction

  10. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Outline Picturing Quantum Processes chapters 4-9 (roughly) 1. Process theory of linear maps 2. quantum maps via ‘doubling’ construction 3. Consequences: purification, causality, no-signalling, no-broadcasting

  11. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Outline Picturing Quantum Processes chapters 4-9 (roughly) 1. Process theory of linear maps 2. quantum maps via ‘doubling’ construction 3. Consequences: purification, causality, no-signalling, no-broadcasting 4. Classical/quantum interaction

  12. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Outline Picturing Quantum Processes chapters 4-9 (roughly) 1. Process theory of linear maps 2. quantum maps via ‘doubling’ construction 3. Consequences: purification, causality, no-signalling, no-broadcasting 4. Classical/quantum interaction 5. Complementarity

  13. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Recap • Wires represent systems , boxes represent processes lists breakfast noise poo cooking baby quicksort lists eggs bacon food love

  14. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Recap • Wires represent systems , boxes represent processes lists breakfast noise poo cooking baby quicksort lists eggs bacon food love • The world is organised into process theories , collections of processes that make sense to combine into diagrams A B C g systems A D ψ h A processes

  15. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Recap • Certain processes play a special role: φ states: effects: numbers: ψ λ

  16. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Recap • Certain processes play a special role: φ states: effects: numbers: ψ λ • State + effect = number, interpreted as: test φ probability ψ state this is called the Born rule .

  17. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity linear maps In the process theory of linear maps :

  18. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity linear maps In the process theory of linear maps : (L1) Every type has a (finite) basis :     g f   g  for all : =  = ⇒ = f i i i

  19. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity linear maps In the process theory of linear maps : (L1) Every type has a (finite) basis :     g f   g  for all : =  = ⇒ = f i i i (L2) Processes can be summed :     g  g    � � �   �   � where f i   h i = h i f f     i i i     g g  

  20. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity linear maps In the process theory of linear maps : (L1) Every type has a (finite) basis :     g f   g  for all : =  = ⇒ = f i i i (L2) Processes can be summed :     g  g    � � �   �   � where f i   h i = h i f f     i i i     g g   (L3) Numbers are the complex numbers : ∈ C λ

  21. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Bases ⇔ process tomography Theorem   j j       g g : = = ⇒ = for all , j i f f     i i

  22. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Bases ⇔ process tomography Theorem   j j       g g for all , j : = = ⇒ = f f i     i i Proof. j j g = f i i

  23. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Bases ⇔ process tomography Theorem   j j       g g for all , j : = = ⇒ = f f i     i i Proof. j j = g f

  24. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Bases ⇔ process tomography Theorem   j j       g g for all , j : = = ⇒ = f f i     i i Proof. g f = j j

  25. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Bases ⇔ process tomography Theorem   j j       g g for all , j : = = ⇒ = f f i     i i Proof. g = f

  26. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Bases ⇔ process tomography Theorem   j j       g g for all , j : = = ⇒ = f f i     i i Proof. g = f

  27. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Bases ⇔ process tomography Theorem   j j       g g for all , j : = = ⇒ = f f i     i i • In other words, f is uniquely fixed by its matrix :   f 1 f 1 f 1 · · · 1 2 m j   f 2 f 2 f 2  · · ·  1 2 m   f j :=   where f . . . ... i   . . . . . .   i f n f n f n · · · 1 2 m

  28. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity What about the Born rule? test φ probability ψ state

  29. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity The Born rule for relations test φ B := { 0 , 1 } ψ state

  30. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity The Born rule for relations possibility test φ B := { 0 , 1 } ψ state

  31. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity The Born rule for linear maps ??? test φ C ψ state

  32. Introduction 1. Linear maps 2. Quantum maps 3. Consequences 4. Classical 5. Complementarity Fixing the problem probability test φ φ R ≥ 0 ψ ψ state

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