In this paper, we report the observation and characterisation of a systematic error in implementation U3 gates IBM quantum computers. By measuring effect gate for various rotation angles appears as an over-rotation, whose magnitude does not correlate with IBM’s cited errors calculated using Clifford randomized benchmarking. We propose simple mitigation procedure to limit effects error. show tha...

Geometric phase phenomena have been observed with single neutrons in polarimeter and interferometer experiments. Interacting with static and timedependent magnetic fields, the state vectors acquire a geometric phase tied to the evolution within spin subspace. In a polarimeter experiment the non-additivity of quantum phases for mixed spin input states is observed. In a Si perfectcrystal interfer...

In the paper it is demonstrated that Bells theorem an unprovable theorem.

We consider a range of “theories” that violate the uncertainty relation for anti-commuting observables derived in [JMP, 49, 062105 (2008)]. We first show that Tsirelson’s bound for the CHSH inequality can be derived from this uncertainty relation, and that relaxing this relation allows for non-local correlations that are stronger than what can be obtained in quantum mechanics. We continue to co...

This work provides a comprehensive approach to analyze the entanglement between subsystems generated by identical particles, based on symmetric/exterior algebra (SEA) and microcausality. Our method amends no-labeling (NLA) quantify any type of particles' entanglement, especially fermions with parity superselection rule. We can non-local properties states in fundamentally equivalent way those fo...

Understanding the characteristics of a quantum systems when affected by noise is one of the biggest challenges for quantum technologies. The general Pauli error channel is an important lossless channel for quantum communication. In this work we consider the effects of a Pauli channel on a pure four-qubit state and simulate the Pauli channel experimentally by studying the action on polarization ...

Device-independent (DI) protocols, such as DI conference key agreement (DICKA) and randomness expansion (DIRE), certify private by observing nonlocal correlations when two or more parties test a Bell inequality. While most protocols are restricted to bipartite tests, harnessing multipartite may lead better performance. Here, we consider tripartite DICKA DIRE based on testing inequalities, speci...

This thesis describes the development of a high-quality source of single-mode fibercoupled polarization-entangled photon pairs based on a collinear spontaneous parametric down-conversion process in a bidirectionally pumped periodically-poled potassium titanyl phosphate (PPKTP) crystal inside a polarization Sagnac interferometer at communication wavelength (1.56 im). A two-photon quantum interfe...

We address the recently posed question as to whether the nonlocality of a single member of an entangled pair of spin 1/2 particles can be shared among multiple observers on the other wing who act sequentially and independently of each other. We first show that the optimality condition for the trade-off between information gain and disturbance in the context of weak or non-ideal measurements eme...