Here we show that spin-lattices can serve as a test object for quantum foundations and quantum information theory, revealing unsuspected properties. We propose a (thought) experiment on such lattices that mimics the Bell- experiment and calculate the outcomes and the Bell inequality. It appears that for a wide range of geometries the Bell- inequality is violated, even if these lattices are local according to the usual definitions. Some spin-1/2 lattices can even violate the Bell inequality more than the Tsirelson bound. We argue that there is no consensual explanation for this result. We make the link with problems in quantum foundations and quantum information theory.
Here we show that spin-lattices can serve as a test object for quantum foundations and quantum information theory, revealing unsuspected properties. We propose a (thought) experiment on such lattices that mimics the Bell- experiment and calculate the outcomes and the Bell inequality. It appears that for a wide range of geometries the Bell- inequality is violated, even if these lattices are local according to the usual definitions. Some spin-1/2 lattices can even violate the Bell inequality more than the Tsirelson bound. We argue that there is no consensual explanation for this result. We make the link with problems in quantum foundations and quantum information theory.
Bell’s inequality is derived by resorting to a hidden-variable theory devised for resolving the Einstein-Bohr debate on the conceptual foundations of quantum mechanics. The legitimacy of quantum superposition for describing the physical world is the essence of the debate. Einstein argued against the legitimacy of quantum superposition. Testing Bell’s inequality by experiments with the experimental results explained by Bell’s theorem opened the door to so-called quantum information technologies. In quantum information theory, “quantum bit” (or “qubit” for short) in a form of quantum superposition is supposed to represent quantum information. In the present paper, a new principle, the general principle of measurements, is introduced and proved as a mathematical theorem. Based on this principle, the experiments for testing Bell’s inequality and so-called experimental evidence for physically realizable “qubit” are scrutinized. The findings are as follows. Although most physicists believe that Einstein’s vision of the physical world contradicts the experimental results of testing Bell’s inequality, actually Einstein’s viewpoint is irrelevant to Bell’s theorem. Bell’s inequality failed to capture the essence of the Einstein-Bohr debate. The experimental results of testing Bell’s inequality and the measurement outcomes of various experiments involving “qubit” are all erroneously explained. Without involving hidden variables, quantum mechanics can be completed based on the general principle of measurements by using disjunction (“or”) as the logical relation between the orthonormal vectors that span an arbitrarily given Hilbert space, and the mathematical setting can remain essentially unchanged. All kinds of “qubit” violate the general principle of measurements and can only describe imaginary objects that do not exist in the real world. A very regrettable conclusion from the above findings is inevitable: Quantum information has no physical carriers, and all quantum information technologies are not physically realizable.
Bell’s inequality is derived by resorting to a hidden-variable theory devised for resolving the Einstein-Bohr debate on the conceptual foundations of quantum mechanics. The legitimacy of quantum superposition for describing the physical world is the essence of the debate. Einstein argued against the legitimacy of quantum superposition. Testing Bell’s inequality by experiments with the experimental results explained by Bell’s theorem opened the door to so-called quantum information technologies. In quantum information theory, “quantum bit” (or “qubit” for short) in a form of quantum superposition is supposed to represent quantum information. In the present paper, a new principle, the general principle of measurements, is introduced and proved as a mathematical theorem. Based on this principle, the experiments for testing Bell’s inequality and so-called experimental evidence for physically realizable “qubit” are scrutinized. The findings are as follows. Although most physicists believe that Einstein’s vision of the physical world contradicts the experimental results of testing Bell’s inequality, actually Einstein’s viewpoint is irrelevant to Bell’s theorem. Bell’s inequality failed to capture the essence of the Einstein-Bohr debate. The experimental results of testing Bell’s inequality and the measurement outcomes of various experiments involving “qubit” are all erroneously explained. Without involving hidden variables, quantum mechanics can be completed based on the general principle of measurements by using disjunction (“or”) as the logical relation between the orthonormal vectors that span an arbitrarily given Hilbert space, and the mathematical setting can remain essentially unchanged. All kinds of “qubit” violate the general principle of measurements and can only describe imaginary objects that do not exist in the real world. A very regrettable conclusion from the above findings is inevitable: Quantum information has no physical carriers, and all quantum information technologies are not physically realizable.
Abstract. Bell inequalities are intended to show that local realist theories cannot describe the world. A local realist theory is one where physical properties are defined prior to and independent of measurement, and no physical influence can propagate faster than the speed of light. Quantum-mechanical predictions for certain experiments violate the Bell inequality while a local realist theory cannot, and this shows that a local realist theory cannot give those quantum-mechanical predictions. However, because of unexpected circumstances or “loopholes ” in available experiment tests, local realist theories can reproduce the data from these experiments. This paper reviews such loopholes, what effect they have on Bell inequality tests, and how to avoid them in experiment. Avoiding all these simultaneously in one experiment, usually called a “loophole-free ” or “definitive ” Bell test, remains an open task, but is very important for technological tasks such as device-independent security of quantum cryptography, and ultimately for our understanding of the world. ar X iv
Bell’s inequality is derived by resorting to a hidden-variable theory devised for resolving the Einstein-Bohr debate on the conceptual foundations of quantum mechanics. The legitimacy of quantum superposition for describing the physical world is the essence of the debate. Einstein argued against the legitimacy of quantum superposition. Testing Bell’s inequality by experiment with the experimental result explained by Bell’s theorem opened the door to so-called quantum information technologies. In quantum information theory, “quantum bit” (or “qubit” for short) in a form of quantum superposition is supposed to carry quantum information. Although most physicists believe that Einstein’s vision of the physical world contradicts the experimental result of testing Bell’s inequality, actually neither the experimental result nor Bell’s theorem is relevant to Einstein’s viewpoint. In the present paper, a new principle, the general principle of measurements, is proved as a mathematical theorem. Based on this principle, the experiment for testing Bell’s inequality and so-called experimental evidence for physically realizable “qubit” are scrutinized. The findings are as follows. The experimental result of testing Bell’s inequality and the measurement outcomes of experiments involving “qubit” are all erroneously explained. Bell’s inequality failed to capture the essence of the Einstein-Bohr debate, and Bell’s theorem is irrelevant to Einstein’s vision of the physical world. Quantum mechanics can be completed by using disjunction (“or”) as the logical relation between the orthonormal vectors that span an arbitrarily given Hilbert space without resorting to any hidden-variable theory, while the mathematical setting will remain essentially unchanged. All kinds of “qubit” violate the general principle of measurements and can only describe imaginary objects that do not exist in the physical world. The findings inevitably lead to a very regrettable conclusion: Quantum information has no physical carers and all quantum information technologies are not physically realizable.
Bell’s inequality is derived by resorting to a hidden-variable theory devised for resolving the Einstein-Bohr debate on the conceptual foundations of quantum mechanics. The legitimacy of quantum superposition for describing the physical world is the essence of the debate. Einstein argued against the legitimacy of quantum superposition. Testing Bell’s inequality by experiments with the experimental result explained by Bell’s theorem opened the door to so-called quantum information technologies. In quantum information theory, “quantum bit” (or “qubit” for short) in a form of quantum superposition is supposed to carry quantum information. In the present paper, a new principle, the general principle of measurements, has been proved as a mathematical theorem. Based on this principle, the experiment for testing Bell’s inequality and so-called experimental evidence for physically realizable “qubit” have been scrutinized. The findings are as follows. Although most physicists believe that Einstein’s vision of the physical world contradicts the experimental result of testing Bell’s inequality, neither the experimental result nor Bell’s theorem is relevant to Einstein’s viewpoint, because Bell’s inequality failed to capture the essence of the Einstein-Bohr debate. The experimental result and the measurement outcomes of various experiments involving “qubit” are all erroneously explained. Quantum mechanics can be completed by using disjunction (“or”) as the logical relation between the orthonormal vectors that span an arbitrarily given Hilbert space without resorting to any hidden-variable theory, while the mathematical setting will remain essentially unchanged. All kinds of “qubit” violate the general principle of measurements and can only describe imaginary objects that do not exist in the real world. A very regrettable conclusion from the above findings is inevitable: All quantum information technologies are not physically realizable, because quantum information has no physical carriers.
Bell inequalities are intended to show that local realist theories cannot describe the world. A local realist theory is one where physical properties are defined prior to and independent of measurement, and no physical influence can propagate faster than the speed of light. Quantum-mechanical predictions for certain experiments violate the Bell inequality while a local realist theory cannot, and this shows that a local realist theory cannot give those quantum-mechanical predictions. However, because of unexpected circumstances or 'loopholes' in available experiment tests, local realist theories can reproduce the data from these experiments. This paper reviews such loopholes, what effect they have on Bell inequality tests, and how to avoid them in experiment. Avoiding all these simultaneously in one experiment, usually called a 'loophole-free' or 'definitive' Bell test, remains an open task, but is very important for technological tasks such as device-independent security of quantum cryptography, and ultimately for our understanding of the world. This article is part of a special issue of Journal of Physics A: Mathematical and Theoretical devoted to '50 years of Bell's theorem'.