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J. Avron

Publications and source records attributed to J. Avron.

5 recordsLinked to original sources
arXiv2022

Lindblad evolutions, Born rule, Heralding and cloning

We discuss an apparent difficulty in computing the radiation emitted by a system undergoing Lindblad evolution. The difficulty is resolved by viewing the problem as Born rule for conserved currents defined by the appropriate terms in the adjoint Lindbladian. In Heralding Alice prepares Bob's system in a state that mirrors her test. We show that heralding is consistent with no-cloning. This follows from the observation that heralding is not a completely positive map.

quant-ph↗
arXiv2021

Quantum advantage and noise reduction in distributed quantum computing

Distributed quantum computing can give substantial noise reduction due to shallower circuits. An experiment illustrates the advantages in the case of Grover search. This motivates studying the quantum advantage of the distributed version of the Simon and Deutsch-Jozsa algorithm. We show that the distributed Simon algorithm retains the exponential advantage, but the complexity deteriorates from O(n) to O(n^2), where n = log2(N). The distributed Deutsch-Jozsa deteriorates to being probabilistic but retains a quantum advantage over classical random sampling.

quant-ph↗
arXiv2006

Entangled Photon Pairs from Semiconductor Quantum Dots

Tomographic analysis demonstrates that the polarization state of pairs of photons emitted from a biexciton decay cascade becomes entangled when spectral filtering is applied. The measured density matrix of the photon pair satisfies the Peres criterion for entanglement by more than 3 standard deviations of the experimental uncertainty and violates Bell's inequality. We show that the spectral filtering erases the ``which path'' information contained in the photons color and that the remanent information in the quantum dot degrees of freedom is negligible.

quant-ph↗
arXiv2001

Hofstadter butterfly as Quantum phase diagram

The Hofstadter butterfly is viewed as a quantum phase diagram with infinitely many phases, labelled by their (integer) Hall conductance, and a fractal structure. We describe various properties of this phase diagram: We establish Gibbs phase rules; count the number of components of each phase, and characterize the set of multiple phase coexistence.

math-ph↗