Density-Matrix Description of the EPR “Paradox”
... observation that qbit A has the value |0A , as implied by Einstein, Podolsky and Rosen [1]? The answer to this is NO. As noted by Peres [7], “Unperformed experiments have no results.” That is, after qbits A and B are prepared in the entangled state (1), these qbits do not have definite “values” unti ...
... observation that qbit A has the value |0A , as implied by Einstein, Podolsky and Rosen [1]? The answer to this is NO. As noted by Peres [7], “Unperformed experiments have no results.” That is, after qbits A and B are prepared in the entangled state (1), these qbits do not have definite “values” unti ...
Why the Disjunction in Quantum Logic is Not Classical1
... left with a siphon, and collecting it in a reference vessel, and the measurement ; does the same at the right. If we test proposition a for the state of the connected vessels containing 20 liters of water, we find that : gives the outcome ``yes'' with certainty, and also ; gives the outcome ``yes'' ...
... left with a siphon, and collecting it in a reference vessel, and the measurement ; does the same at the right. If we test proposition a for the state of the connected vessels containing 20 liters of water, we find that : gives the outcome ``yes'' with certainty, and also ; gives the outcome ``yes'' ...
Available PDF download
... There are a number of different approaches to quantum gravity. One natural avenue is to retain the interplay between gravity and geometry but now use quantum Riemannian geometry in place of the standard, classical one. This is the key idea underlying loop quantum gravity. There are several calculat ...
... There are a number of different approaches to quantum gravity. One natural avenue is to retain the interplay between gravity and geometry but now use quantum Riemannian geometry in place of the standard, classical one. This is the key idea underlying loop quantum gravity. There are several calculat ...
QUANTUM MAPS
... Quantization of a dynamical system has two components: kinematic and dynamic. The kinematic component involves the construction of a suitable quantized phase space of the system. This quantized phase space is given in terms of a non-commutative algebra A} of observables. In the language of non-commu ...
... Quantization of a dynamical system has two components: kinematic and dynamic. The kinematic component involves the construction of a suitable quantized phase space of the system. This quantized phase space is given in terms of a non-commutative algebra A} of observables. In the language of non-commu ...
White paper: The logic of quantum mechanics
... 19] and the other ones which have been around is our choice of primitive concepts: • We aim to axiomatize the tensor product structure, that is, how two quantum entities make up one whole. Most other approaches start from measurement-related concepts, be it either spaces of observables, spaces of pr ...
... 19] and the other ones which have been around is our choice of primitive concepts: • We aim to axiomatize the tensor product structure, that is, how two quantum entities make up one whole. Most other approaches start from measurement-related concepts, be it either spaces of observables, spaces of pr ...
Complexity of one-dimensional spin chains
... comptuation: Shepherd, Franz, and Werner (quantph/0512058) construct a universal 1-dimensional quantum cellular automaton with 12 states per site. • Finding specific properties, like the ground state energy, one might expect to be easier, because after all there is just one number to know, and indee ...
... comptuation: Shepherd, Franz, and Werner (quantph/0512058) construct a universal 1-dimensional quantum cellular automaton with 12 states per site. • Finding specific properties, like the ground state energy, one might expect to be easier, because after all there is just one number to know, and indee ...
IOSR Journal of Applied Physics (IOSR-JAP)
... Abstract:Raman scattering process and itscorrespondingspectrum is widely used in science and industry. This process was explained by using classical physics and quantum harmonic model. Recently Schrödinger equation was used to explain this phenomenon. In this work semi classical model is used to pro ...
... Abstract:Raman scattering process and itscorrespondingspectrum is widely used in science and industry. This process was explained by using classical physics and quantum harmonic model. Recently Schrödinger equation was used to explain this phenomenon. In this work semi classical model is used to pro ...
Quantum - National Physical Laboratory
... data is not straight-forward, as the data signals are typically much, much stronger than quantum ones, scattered light from the data lasers can easily contaminate and overwhelm the quantum photons, rendering QKD impossible. These problems have meant that previous single fibre demonstrations of combi ...
... data is not straight-forward, as the data signals are typically much, much stronger than quantum ones, scattered light from the data lasers can easily contaminate and overwhelm the quantum photons, rendering QKD impossible. These problems have meant that previous single fibre demonstrations of combi ...
Why Life Exists?
... there is in fact a tremendous degree of coherence within all living systems. The accelerating electrons explain not only the Maxwell Equations and the Special Relativity, but the Heisenberg Uncertainty Relation, the Wave-Particle Duality and the electron’s spin also, building the Bridge between the ...
... there is in fact a tremendous degree of coherence within all living systems. The accelerating electrons explain not only the Maxwell Equations and the Special Relativity, but the Heisenberg Uncertainty Relation, the Wave-Particle Duality and the electron’s spin also, building the Bridge between the ...
Hong-Ou-Mandel interference between triggered and heralded
... It provides a fundamental primitive for the coherent interfacing of separate quantum systems via their emitted photons [3] as an alternative to their direct interaction [4, 5]. It is the basis of quantum teleportation [6–8] and entanglement swapping [9, 10]. Initially developed as a sensitive tool f ...
... It provides a fundamental primitive for the coherent interfacing of separate quantum systems via their emitted photons [3] as an alternative to their direct interaction [4, 5]. It is the basis of quantum teleportation [6–8] and entanglement swapping [9, 10]. Initially developed as a sensitive tool f ...
Quantum key distribution
Quantum key distribution (QKD) uses quantum mechanics to guarantee secure communication. It enables two parties to produce a shared random secret key known only to them, which can then be used to encrypt and decrypt messages. It is often incorrectly called quantum cryptography, as it is the most well known example of the group of quantum cryptographic tasks.An important and unique property of quantum key distribution is the ability of the two communicating users to detect the presence of any third party trying to gain knowledge of the key. This results from a fundamental aspect of quantum mechanics: the process of measuring a quantum system in general disturbs the system. A third party trying to eavesdrop on the key must in some way measure it, thus introducing detectable anomalies. By using quantum superpositions or quantum entanglement and transmitting information in quantum states, a communication system can be implemented which detects eavesdropping. If the level of eavesdropping is below a certain threshold, a key can be produced that is guaranteed to be secure (i.e. the eavesdropper has no information about it), otherwise no secure key is possible and communication is aborted.The security of encryption that uses quantum key distribution relies on the foundations of quantum mechanics, in contrast to traditional public key cryptography which relies on the computational difficulty of certain mathematical functions, and cannot provide any indication of eavesdropping at any point in the communication process, or any mathematical proof as to the actual complexity of reversing the one-way functions used. QKD has provable security based on information theory, and forward secrecy.Quantum key distribution is only used to produce and distribute a key, not to transmit any message data. This key can then be used with any chosen encryption algorithm to encrypt (and decrypt) a message, which can then be transmitted over a standard communication channel. The algorithm most commonly associated with QKD is the one-time pad, as it is provably secure when used with a secret, random key. In real world situations, it is often also used with encryption using symmetric key algorithms like the Advanced Encryption Standard algorithm. In the case of QKD this comparison is based on the assumption of perfect single-photon sources and detectors, that cannot be easily implemented.