Abstract We consider Margenau-Hill quasiprobability that measures a statistical weight assigned to an observation of an energy eigenvalue pair and its utilization in assessing work done by isolated quantum ensembles that generally contain coherence. We point out some physically reasonable and intuitive features of the statistical properties of work determined by Margenau-Hill quasiprobability. To be specific, we show that in sharp contrast to other proposals, the moment-generating function given by Margenau-Hill quasiprobability fulfills the composition and shift properties, and thus guarantees the additivity of works performed by joined work protocols. Work fluctuations accessed by Margenau-Hill distribution also give expected values for initially pure energy ensembles, providing a rationale as to why it serves as a unique measure in characterizing quantum work and its fluctuations.
Measurement incompatibility and the negativity of quasi-probability distributions both demonstrate the signature of nonclassicality. However, their relations largely remained qualitative, and no explicit operational connection has been established. We provide an operational link between measurement incompatibility and the Margenau-Hill(MH) quasi-probability distribution associated with two dichotomic observables. { We first derive the joint measurability (measurement compatibility) condition for any pair of dichotomic observables in arbitrary finite dimension
d.} We then rigorously prove that for any pair of unsharp dichotomic measurements in dimension
d, the positivity of the MH distribution is equivalent to joint measurability \emph{i.e.}, the MH distribution is positive \emph{if and only if} the measurements are jointly measurable. We further introduce the MH-like quasi-probability distribution for
n dichotomic unsharp observables in arbitrary finite dimension and derive a sufficient condition of joint-measurability when the observables are mutually anticommuting. Finally, we propose an interferometric setup, inspired by quantum-switch architectures, that directly reconstructs MH quasi-probability which in turn provides a test of incompatibility.
A realizable quantum three-pass protocol authentication based on Hill-cipher algorithm is presented by encoded and decoded plaintext using classical Hill-cipher algorithm. It is shown that the encoded message transferred to the particles called quantum state where we assumed that a photon is used as a qubit and after the encoded message is transferred into photons, the polarization of each photon is rotated by an angle θj , which is chosen randomly for each qubit. The sender and receiver agree over a Hill-cipher key, the encryption occurs by utilization of the quantum three-pass protocol (QTPP), the decryption will be illustrated, and an example shows how the algorithm will work. Finally, the security of this algorithm is analyzed in detail.