1999/07/03 by M. Dugić, Miroljub Dugic, Dugic, Miroljub
Engineering · Physics and Astronomy · #Advancements in Semiconductor Devices and Circuit Design #FOS: Physical sciences #Integrated Circuits and Semiconductor Failure Analysis #Quantum Physics (quant-ph) #Semiconductor materials and devices #quant-ph
paper · pdf · doi:10.48550/arxiv.quant-ph/9907011
A short version. PlainTex, 28 pages, no figures
arxiv created 1999/07/03 · openalex publication_date 1999/07/03 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
We consider the CNOT quantum gate as a physical action, i.e. as unitary in time evolution of the two-qubit system. This points to the modeling of the interaction Hamiltonian of the two-qubit system which would correspond to the CNOT transformation; the analysis naturally generalizes to the Toffoli gate. Despite nonuniqueness of the model of the interaction Hamiltonian, the analysis distinguishes that the interaction Hamiltonian does not posses any global (rotational) symmetry. This forces us to conclude that the direct (non-mediated) interaction in the two-qubit system does not suffice for implementing the CNOT gate. I.e., so as to be able succesfully to implement the CNOT transformation, a mediator (i.e. an external physical system interacting with both of the qubits) is required.