Unitarity as Preservation of Entropy and Entanglement in Quantum
... and counterintuitive properties of quantum mechanics—entanglement— appears only in joint quantum systems. This quantum “inseparability” had for many decades questioned the logical structure of QM and raised a fundamental philosophical debate.(1) The most famous apparent “paradox” aroused by the nonl ...
... and counterintuitive properties of quantum mechanics—entanglement— appears only in joint quantum systems. This quantum “inseparability” had for many decades questioned the logical structure of QM and raised a fundamental philosophical debate.(1) The most famous apparent “paradox” aroused by the nonl ...
Continuous Variable Quantum Information: Gaussian States and
... with a variety of quantum hardware, and entered a stage of commercial exploitation [6]. The time seems ripe for selected quantum computing devices to live up to their high expectations [7]. Traditionally, two main approaches to quantum information processing have been pursued. On one hand, a “digita ...
... with a variety of quantum hardware, and entered a stage of commercial exploitation [6]. The time seems ripe for selected quantum computing devices to live up to their high expectations [7]. Traditionally, two main approaches to quantum information processing have been pursued. On one hand, a “digita ...
Quantum Gates and Simon`s Algorithm
... Basic Facts About Boolean Functions Boolean functions Any function f : {0, 1}n → {0, 1}m , where n is the number of input bits and m the number of output bits is said to be a Boolean function. Any Boolean function can be represented by a truth table. If f = (f1 , . . . , fm ), this is a matrix of s ...
... Basic Facts About Boolean Functions Boolean functions Any function f : {0, 1}n → {0, 1}m , where n is the number of input bits and m the number of output bits is said to be a Boolean function. Any Boolean function can be represented by a truth table. If f = (f1 , . . . , fm ), this is a matrix of s ...
Dual universality of hash functions and its
... the Toeplitz matrix X and the identity matrix I, mentioned in Section II. ...
... the Toeplitz matrix X and the identity matrix I, mentioned in Section II. ...
Spin-entangled electrons - Theoretical Physics at University of
... The definition of mixed state entanglement is somewhat more general and will be discussed further below. ...
... The definition of mixed state entanglement is somewhat more general and will be discussed further below. ...
Spontaneous Formation of Magnetic Moments and Dephasing in Two-Dimensional Disordered Systems
... picture, and possibly with the general quantum mechanical principle described above. One possible explanation for this saturation is magnetic impurities: At temperatures higher than the Kondo temperature, there is a finite probability for spin flip scattering that will cause dephasing. Follow-up exp ...
... picture, and possibly with the general quantum mechanical principle described above. One possible explanation for this saturation is magnetic impurities: At temperatures higher than the Kondo temperature, there is a finite probability for spin flip scattering that will cause dephasing. Follow-up exp ...
Single component and binary mixtures of BECs in double
... If the system is fully condensed, then the eigenvalues are 1 and 0. The eigenvector corresponding to 1 is, Departure from 0,1 indicates the system is fragmented B. Juliá-Díaz, Trobades Científiques de la Mediterrània, Menorca, 2010 ...
... If the system is fully condensed, then the eigenvalues are 1 and 0. The eigenvector corresponding to 1 is, Departure from 0,1 indicates the system is fragmented B. Juliá-Díaz, Trobades Científiques de la Mediterrània, Menorca, 2010 ...
Linear Logic for Generalized Quantum Mechanics
... complementarity and Heisenberg uncertainty in linear automata. Our claim is that these are the analogues for ordered time of the phenomena of those names encountered in orthodox quantum mechanics. The corresponding mathematical basis for the the respective complementarities is duality: Stone duality ...
... complementarity and Heisenberg uncertainty in linear automata. Our claim is that these are the analogues for ordered time of the phenomena of those names encountered in orthodox quantum mechanics. The corresponding mathematical basis for the the respective complementarities is duality: Stone duality ...
Chapter 2 Challenging the Boundaries between Classical and
... to be in agreement with the theoretical values. The results did not provide an unambiguous arbitration concerning the two possible theoretical mechanisms (mechanical or quantum) causing the proper frequency of optical dispersion, for the empirical value was consistent with both. However, since the m ...
... to be in agreement with the theoretical values. The results did not provide an unambiguous arbitration concerning the two possible theoretical mechanisms (mechanical or quantum) causing the proper frequency of optical dispersion, for the empirical value was consistent with both. However, since the m ...
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.