Papers by BELLO sadiq muhammad
Physical Review Letters, 2020
Nature communications, Oct 12, 2018
A physical theory is called non-local when observers can produce instantaneous effects over dista... more A physical theory is called non-local when observers can produce instantaneous effects over distant systems. Non-local theories rely on two fundamental effects: local uncertainty relations and steering of physical states at a distance. In quantum mechanics, the former one dominates the other in a well-known class of non-local games known as XOR games. In particular, optimal quantum strategies for XOR games are completely determined by the uncertainty principle alone. This breakthrough result has yielded the fundamental open question whether optimal quantum strategies are always restricted by local uncertainty principles, with entanglement-based steering playing no role. In this work, we provide a negative answer to the question, showing that both steering and uncertainty relations play a fundamental role in determining optimal quantum strategies for non-local games. Our theoretical findings are supported by an experimental implementation with entangled photons.
Science Advances, 2017
Demonstration of the superadditivity of two quantum information resources with three-partite nond... more Demonstration of the superadditivity of two quantum information resources with three-partite nondistillable entangled states.
Pakistan Journal of Biological Sciences, 1999
Methods were developed to optimize the media for callus induction from mature embryos of indica r... more Methods were developed to optimize the media for callus induction from mature embryos of indica rice (Oryza sativa L.) CV. DM-25. Callusing from seeds of rice was observed with various levels of 2,4-d alone and in combination with different concentratiom of benzyl adenine. With the gradual increase of 2,4-d concentration in callus induction medium, there was gradual increase in callusing frequency.
Physical Review X, 2014
Quantum methods allow to reduce communication complexity of some computational tasks, with severa... more Quantum methods allow to reduce communication complexity of some computational tasks, with several separated partners, beyond classical constraints. Nevertheless, experimental demonstrations of this fact are thus far limited to some abstract problems, far away from real-life tasks. We show here, and demonstrate experimentally, that the power of reduction of communication complexity can be harnessed to gain advantage in famous, immensely popular, card game-Bridge. The essence of a winning strategy in Bridge is efficient communication between the partners. The rules of the game allow only specific form of communication, of a very low complexity (effectively one has a strong limitations on number of exchanged bits). Surprisingly, our quantum technique is not violating the existing rules of the game (as there is no increase in information flow). We show that our quantum Bridge auction corresponds to a biased nonlocal Clauser-Horne-Shimony-Holt (CHSH) game, which is equivalent to a 2 → 1 quantum random access code. Thus our experiment is also a realization of such protocols. However, this correspondence is not full which enables the Bridge players to have efficient strategies regardless of the quality of their detectors.
Scientific Reports, 2015
Entanglement is one of the most puzzling features of quantum theory and of great importance for t... more Entanglement is one of the most puzzling features of quantum theory and of great importance for the new field of quantum information. The determination whether a given state is entangled or not is one of the most challenging open problems of the field. Here we report on the experimental demonstration of measurement-device-independent (MDI) entanglement detection using witness method for general two qubits photon polarization systems. In the MDI settings, there is no requirement to assume perfect implementations or neither to trust the measurement devices. This experimental demonstration can be generalized for the investigation of properties of quantum systems and for the realization of cryptography and communication protocols.
Pakistan Journal of Biological Sciences, 1999
Scientific Reports, 2013
Understanding the characteristics of a quantum systems when affected by noise is one of the bigge... more 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 encoded entangled photons. When the noise channel acting on the photons is correlated, a set spanned by four orthogonal bound entangled states can be generated. We study this interesting case experimentally and demonstrate that products of Bell states can be brought into a bound entangled regime. We find states in the set of bound entangled states which experimentally violate the CHSH inequality while still possessing a positive partial transpose. C oherent superpositions and entanglement are key resources in quantum communication and computation tasks. Quantum methods and techniques rely on the preparation, transmission, processing, and detection of quantum states. But quantum states are very fragile and easily destroyed by decoherence processes due to unwanted coupling with the environment. These uncontrollable influences cause noise in the communication or errors in the outcome of a computation, and thus reduce the advantages of quantum information resources. To overcome the decoherence problem, several purification and distillation protocols have been proposed and implemented, each of them appropriate for a specific type of coupling with the environment 1-7. These protocols use local operations assisted by classical communications (LOCC). In most protocols the parties involved are distributed in separated locations, local operations is then a natural restriction since the parties involved can coordinated by classical communication the operations they will do on their own qubits. It has been shown that there is a class of noisy non-separable quantum states where no entanglement can be distilled. This entanglement class has been termed bound entanglement (BE) 8. These BE states live in the ''gray'' area between the separable (classical) and distillable non-separable (free entangled) states. One way to create such an irreversible noisy state is to start with a pure entangled state and then subject it to stochastic local actions which bring the state into the BE regime. These stochastic local actions can be modelled by an LOCC action and is considered to occur during the transmission of the qubits to the parties. In order to detect BE, one can use the positive partial transpose (PT) method 9 combined with an entanglement indicator such as the witness method. Even though BE is regarded as a weak form of entanglement, it has been shown that some BE states can maximally violate the CHSH inequality 10,11. Thus there is no hidden variable model that can be assigned to such states. Moreover, it has been shown that BE can be used as a resource in quantum communication tasks such as secret sharing, key distribution 12 , superactivation 13 , and super-additivity of channel capacity 14. BE has been demonstrated experimentally only very recently 15-19. In all these experiments, a large amount of depolarized noise was added to reach the BE regime, which prevented a violation of the CHSH inequality. From the perspective of quantum communication applications the violation of a Bell inequality is closely related to the reduction of communication complexity 20. Further experimental investigations are therefore needed to understand how noise affects quantum states and how BE-states are generated. Our objective is thus to identify those situations when the distributed states are in a BE-regime that is useful for quantum communication. In this work we focus on highly symmetric four-qubit BE states which are generated through a Pauli channel 21-23. Results Modelling the pauli quantum channel. Here we consider a lossless decoherence channel induced by an environment when pure entangled states are to be distributed. Suppose four separated parties Alice (A), Bob (B), Charlie (C), and David (D) like to share two pure bipartite entangled states among each other. The state considered here is two-Bell-state-like,
Pakistan Journal of Biological Sciences, 2000
The correlation coefficient analysis showed that all the characters observed in this experiment h... more The correlation coefficient analysis showed that all the characters observed in this experiment have positive correlation with yield of seed cotton per plant. As regards the significance of correlation, these differ in respect as number of bolls per plant and average boll weight are highly significant while staple length has significant correlation and seed inde, lint index and ginning outturn are non significant. The value of coefficients of determination revealed that larger proportion of probability in yield was accounted for number of bolls per plant.
Journal of Astrophysics and Astronomy, 2008
The difference between Universal time (UT) and Dynamical time (TD), known as Delta T (T) is tabul... more The difference between Universal time (UT) and Dynamical time (TD), known as Delta T (T) is tabulated for the first day of each year in the Astronomical Almanac. During the last four centuries it is found that there are large differences between its values for two consecutive years. Polynomial approximations have been developed to obtain the values of T for any time of a year for the period AD 1620 to AD 2000 (Meeu 2000) as no dynamical theories describe the variations in T. In this work, a new set of polynomials for T is obtained for the period AD 1620 to AD 2007 that is found to produce better results compared to previous attempts.
Which is the simplest logical structure for which there is quantum nonlocality? We show that ther... more Which is the simplest logical structure for which there is quantum nonlocality? We show that there are only three bipartite Bell inequalities with quantum violation associated with the simplest graph of relationships of exclusivity with a quantum-classical gap. These are the most elementary logical Bell inequalities. We show that the quantum violation of some well-known Bell inequalities is related to them. We test the three Bell inequalities with pairs of polarization-entangled photons and report violations in good agreement with the quantum predictions. Unlike other experiments testing noncontextuality inequalities with pentagonal exclusivity, the ones reported here are free of the compatibility loophole.
Applied Geomatics, 2010
This study mainly focuses on the solution of the vertical gravity anomaly gradient and determinat... more This study mainly focuses on the solution of the vertical gravity anomaly gradient and determination of its effect on the total geoid-quasigeoid separation. Due to its small effect on geoid-quasigeoid separation, the planar approximation of vertical gravity anomaly in the innermost zone has been implemented. The computation of a strongly singular integral expressing the vertical gravity anomaly gradient was used for this purpose for even order (up to n=6) of the Simpson and Newton-Cotes integration technique. The derivation of the relationships for different integration radii has been made to obtain these solutions using gridded data of free air anomaly. The comparison of relationships for the different integration radii was made in order to select an optimum radius of the integration in planar approximation for the vertical gravity anomaly gradient dependent geoidquasigeoid separation term. The integration radii of 3.1, 6.2 and 9.3 km show an increasing behaviour towards saturation. The effect of vertical gravity anomaly gradient has similar pattern on the geoid-quasigeoid separation term towards saturation. The saturation trend for vertical gravity anomaly gradient is comparatively faster than its corresponding geoidquasigeoid separation dependent term. The results also show that 2nd order Newton-Cotes integration is found to be comparable with the approximate linear solution for the vertical gravity anomaly gradient given by Heiskanen and Moritz. The vertical gravity anomaly dependant term has a rather small effect on geoid-quasigeoid separation in the mid elevation range and ranges from −6.18 to 2.7 mm for n=6. The findings of the study leads to the inferences that the order of integration should be selected either n=4 or n=6 for better estimates of vertical gravity anomaly gradient solution. This criterion is also valid for their effect on geoidquasigeoid separation with planar approximation in the innermost zone for the low-to mid-range elevation areas.
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Papers by BELLO sadiq muhammad