In device-independent quantum information, correlations between local measurement outcomes observed by spatially separated parties in a Bell test play fundamental role. Even though it is long-known that the set of allowed theory lies strictly Bell-local and no-signaling set, many questions concerning geometry remain unanswered. Here, we revisit problem when boundary coincides with simplest scenario. particular, for each Class these common boundaries containing <mml:math...

Certification of quantum systems and their properties has become a field intensive study. Here, taking advantage the one-sided device-independent (1SDI) scenario (also known as steering scenario), we propose self-testing scheme for all bipartite entangled states using single family inequalities with minimal number two measurements per party. Building on this then show how to certify rank-one extremal measurements, including nonprojective ${d}^{2}$-outcome which in turn can be used...

A scheme for characterizing entanglement using the statistical measure of correlation given by Pearson coefficient (PCC) was recently suggested that has remained unexplored beyond qubit case. Towards application this high dimensional states, a key step been taken in very recent work experimentally determining PCC and analytically relating it to Negativity quantifying empirically produced bipartite pure state spatially correlated photonic qutrits. Motivated work, we present here comprehensive...

While it has recently been demonstrated how to certify the maximal amount of randomness from any pure two-qubit entangled state in a device-independent way [E. Woodhead et al., Phys. Rev. Research 2, 042028(R)(2020)], problem optimal certification states higher local dimension remains open. Here we introduce method for possible $2\log_23$ random bits using bipartite two-qutrit and extremal nine-outcome general non-projective measurements. To this aim, exploit extended Bell scenario...

We demonstrate one-sided device-independent self-testing of any pure two-qubit entangled state based on a fine-grained steering inequality. The maximum violation inequality can be used to witness certain steerable correlations, which certify all states. Our experimental results identify particular has been self-tested and measurement operators are the untrusted side. Furthermore, we analytically derive robustness bound our protocol, enabling subsequent verification through tomography....

Einstein-Podolsky-Rosen steering is an intermediate relationship between entanglement and Bell nonlocality in the hierarchical structure of quantum nonlocality. To certify steerability entangled state, Mermin inequality supposed to be violated by exceeding bound 2. We present experimental generation post-selected three-photon states witness a maximal violation up 3.50±0.05. In context observing which requires measuring on GHZ we derive tight lower GHZ-fidelity that can certified from...

This work shows that ``self-testing'' in quantum devices is possible any experimental scenario involving an arbitrary number of local measurements performed on subsystems. Moreover, it provides numerical evidence showing these self-testing statements are robust, i.e., could tolerate imperfections realizations.

Self-testing of quantum devices based on observed measurement statistics is a method to certify systems using minimal resources. In Irfan et al. [A. A. M. Irfan, K. Mayer, G. Ortiz, and E. Knill, Phys. Rev. A 101, 032106 (2020)] scheme observing that demonstrate Kochen-Specker contextuality has been shown two-qubit entangled states measurements without the requirement spatial separation between subsystems. However, this assumes set compatibility conditions which are crucial demonstrating...

Recently, a weak form of quantum steering, i.e., certification steering in one-sided semi-device-independent way, has been formulated [Jebarathinam et al. Phys. Rev. A 108, 042211 (2023)]. In this work, for two-qubit states, we study the relationships between quantification steerability and information-theoretic simultaneous correlations mutually unbiased bases [Wu Scientific Reports 4, 4036 (2014)]. For states that belong to Bell-diagonal quantifying provides an operational characterization...

In recent years, exploration of the possible use separable states as a resource to achieve quantum information processing (QIP) tasks has been gaining increasing significance. this context, particularly important demonstration that nonvanishing discord is necessary condition for be used remotely preparing any arbitrary pure target state [Nat. Phys. 8, 666 (2012)]. The present work stems from our observation not only can with same imply different efficiencies (in terms average fidelity)...

We show how nonclassical correlations in local bipartite states can act as a resource for quantum information processing. Considering the task of random access codes (RACs) through separable Bell-diagonal states, we demonstrate advantage superunsteerability over classical protocols assisted with two bits shared randomness. propose measure which quantifies nonclassicality beyond steering and obtain its analytical expression context two- three-setting scenarios that are directly related to...

A random access code (RAC) is an important communication protocol to obtain information about a randomly specified substring of $n$-bit string, while only having limited the string. Quantum RACs usually utilize either quantum bits or shared-in-advance state used in conjunction with classical communication. Here we consider latter version protocols under constraint single-bit and shared arbitrary two qubits. Taking worst-case success probability as figure merit, demonstrate that any...

Characterization of quantum devices received from unknown providers is a significant primary task for any information processing protocol. Self-testing protocols are designed this purpose certifying components the observed statistics under set minimal assumptions. Here we propose self-testing protocol binary Pauli measurements employing violation Leggett-Garg inequality. The scenario based on temporal correlations does not require entanglement, costly and fragile resource. Moreover, unlike...

We propose a family of noncontextuality inequalities and show that they can be used for certification multiqubit quantum systems. Our scheme, unlike those based on nonlocality, does not require spatial separation between the subsystems, yet it makes use certain compatibility relations measurements. Moreover, is scalable in sense number expectation values are to measured observe contextuality scales polynomially with qubits being certified. In particular case we also our scheme robust errors...

Contextuality is a fundamental manifestation of nonclassicality, indicating that for certain quantum correlations, sets jointly measurable variables cannot be pre-assigned values independently the measurement context. In this work, we characterize nonclassical correlation beyond contextuality, in terms supernoncontextuality, namely higher-than-quantum hidden-variable(HV) dimensionality required to reproduce given noncontextual correlations. Thus supernoncontextuality contextuality analogue...

Demonstrating contextual correlations in quantum theory through the violation of a non-contextuality inequality necessarily needs some ``contexts" and thus assumes compatibility relations between measurements. As result, any self-testing protocol based on maximal such is not free from assumptions. In this work, we propose temporal inequalities derived for multi-qubit systems without assuming among We demonstrate that new can be maximally violated via sequential measurement scenario....

Abstract Demonstrating contextual correlations in quantum theory through the violation of a non-contextuality inequality necessarily needs some ‘contexts’ and thus assumes compatibility relations between measurements. As result, any self-testing protocol based on maximal such is not free from assumptions. In this work, we propose temporal inequalities derived for multi-qubit systems without assuming among We demonstrate that new can be maximally violated via sequential measurement scenario....

Quantum discord can demonstrate quantum nonlocality in the context of a semi-device-independent Bell or steering scenario, i.e., by assuming only Hilbert-space dimension. This work addresses which aspect bipartite coherence is essential to such information tasks going beyond standard steering. It has been shown that global single system be transformed into entanglement. However, also present discord. At same time, display locally, subsystem both subsystems. Thus, separable states defined...

We introduce the measures, Bell discord (BD) and Mermin (MD), to characterize bipartite quantum correlations in context of nonsignaling (NS) polytopes. These measures divide full NS polytope into four regions depending on whether BD and/or MD is zero. This division allows us obtain a 3-decomposition that any box with two binary inputs outputs can be decomposed Popescu-Rohrlich (PR) box, maximally local equal quantify types nonclassicality arising from all correlated states which are neither...

Superunsteerability is a particular kind of spatial quantum correlation that can be observed in steering scenario the presence limited shared randomness. In this work, we define an experimentally measurable quantity to certify superunsteerability. context certification randomness with scenario, demonstrate such superunsteerability provides bound on amount genuine generation. On other hand, superlocality another Bell We identify inequalities scenarios adopted implement $2$-to-$1$ and...

Superlocality and superunsteerability provide operational characterization of quantum correlations in certain local unsteerable states, respectively. Such correlated states have a nonzero discord. A two-way discord is necessary for pointed out by superlocality. On the other hand, this work, we demonstrate that not to superunsteerability. To end, one-way discordant states. This turn implies existence also presence without Superunsteerability occurrence steerability one-sided...

We discuss the problem of separating total correlations in a given quantum joint probability distribution into nonlocality, contextuality and classical correlations. Bell discord Mermin which qunatify nonlocality are interpreted as distance measures nonsignaling polytope. A measure is introduced to divide amount purely nonclassical part part. show that satisfy additivity relations among these three measures.

Certification of quantum systems and their properties has become a field intensive studies. Here, taking advantage the one-sided device-independent scenario (known also as steering scenario), we propose self-testing scheme for all bipartite entangled states using single family inequalities with minimal number two measurements per party. Building on this then show how to certify rank-one extremal measurements, including non-projective $d^2$-outcome which in turn can be used certification...

The present work is motivated by the question as to what aspect of correlation entailed two-qubit state serves appropriate quantitative resource for steering. To this end, considering Bell-diagonal states, suitable measures simultaneous correlations in two and three complementary (mutually unbiased) bases are identified relevant resources quantum Quantitative relations between steering corresponding demonstrated which ensure that qubit steerable higher value mutually unbiased necessarily...