Virtual Quantum Subsystems

  title={Virtual Quantum Subsystems},
  author={Paolo Zanardi Institute for Scientific Interchange Foundation and Istituto Nazionale per la Fisica della Materia},
The physical resources available to access and manipulate the degrees of freedom of a quantum system define the set A of operationally relevant observables. The algebraic structure of A selects a preferred tensor product structure i.e., a partition into subsystems. The notion of compoundness for quantum system is accordingly relativized. Universal control over virtual subsystems can be achieved by using quantum noncommutative holonomies 
Localizable quantum coherence
Locality and entanglement of indistinguishable particles
It is proved that three of the aforementioned five entanglement definitions are incompatible with any locality notion defined as above.
Entanglement and indistinguishability in a quantum ontology of properties.
The Correspondence Principle and the Understanding of Decoherence
Although Bohr’s Correspondence Principle (CP) played a central role in the first versions of quantum mechanics, its original version seems to have no present-day relevance. The purpose of the present
Nonlocality of observable algebras in quasi-Hermitian quantum theory
Explicit construction of local observable algebras in quasi-Hermitian quantum theories is derived in both the tensor product model of locality and in models of free fermions. The latter construction
Decoherence as a sequence of entanglement swaps
  • C. Fields
  • Computer Science
    Results in Physics
  • 2019


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Let us consider two qubits and the family by U λ := exp(i λ S) = cos λ 1 1 + i sin λ S where S |ψ ⊗ |φ = |φ ⊗ |ψ). If X1 := σx ⊗ 1 1 one has X1(U λ ) = cos 2 λ X1 + sin 2 λ 1 1 ⊗ σx + i
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    ) implies A2 ⊂ ⊕J Mn J (C) ⊗ 1 1 d J then A1 ∨ A2 = ⊕J Mn J (C) ⊗ M d J (C). A comparison of the dimension of this latter algebra
    • When A1 is not Eq