Quantum Mechanics as Quantum Information
... The Lorentz transformations have the name they do, rather than, say, the Einstein transformations, for good reason: Lorentz had published some of them as early as 1895. Indeed one could say that most of the empirical predictions of special relativity were in place well before Einstein came onto the ...
... The Lorentz transformations have the name they do, rather than, say, the Einstein transformations, for good reason: Lorentz had published some of them as early as 1895. Indeed one could say that most of the empirical predictions of special relativity were in place well before Einstein came onto the ...
10 Time Reversal Symmetry in Quantum Mechanics
... If x → x, p → −p under time reversal, then this commutation relation no longer holds. How to solve this problem? It was realized by Wigner that in quantum mechanics, time reversal has to be defined in a very special way different from all other symmetries. Time reversal operator is anti-unitary: it ...
... If x → x, p → −p under time reversal, then this commutation relation no longer holds. How to solve this problem? It was realized by Wigner that in quantum mechanics, time reversal has to be defined in a very special way different from all other symmetries. Time reversal operator is anti-unitary: it ...
104,18415 (2007)
... the errors induced by local perturbations are exponentially suppressed ⬃exp(⫺L/), where L is the linear size of the system and is a characteristic length inversely proportional to the excitation gap (3, 4). In the ground state sector, one thus has a topologically protected two-state system that, ...
... the errors induced by local perturbations are exponentially suppressed ⬃exp(⫺L/), where L is the linear size of the system and is a characteristic length inversely proportional to the excitation gap (3, 4). In the ground state sector, one thus has a topologically protected two-state system that, ...
Quantum walk search on satisfiability problems random
... with identical design scale in performance in the same way. Since again the ...
... with identical design scale in performance in the same way. Since again the ...
Quantum fluctuation relations: Foundations and applications
... tailored two-point correlation functions of corresponding stationary nonequilibrium fluctuations of the underlying unperturbed, stationary nonequilibrium system (Hänggi, 1978; Hänggi and Thomas, 1982). They coined the expression ‘‘fluctuation theorems’’ for these relations. As in the near thermal ...
... tailored two-point correlation functions of corresponding stationary nonequilibrium fluctuations of the underlying unperturbed, stationary nonequilibrium system (Hänggi, 1978; Hänggi and Thomas, 1982). They coined the expression ‘‘fluctuation theorems’’ for these relations. As in the near thermal ...
PDF
... Ubiquitous, reliable, high data-rate communication—carried by electromagnetic waves at microwave to optical frequencies—is an essential ingredient of our technological age. Information theory seeks to delineate the ultimate limits on reliable communication that arise from the presence of noise and o ...
... Ubiquitous, reliable, high data-rate communication—carried by electromagnetic waves at microwave to optical frequencies—is an essential ingredient of our technological age. Information theory seeks to delineate the ultimate limits on reliable communication that arise from the presence of noise and o ...
presentation pdf - EMERGENT QUANTUM MECHANICS
... These are the LOCAL expressions for the energy-momentum of the particle. Conservation of energy is maintained through the quantum Hamilton-Jacobi equation. Similar relations hold for the Pauli and Dirac particles. ...
... These are the LOCAL expressions for the energy-momentum of the particle. Conservation of energy is maintained through the quantum Hamilton-Jacobi equation. Similar relations hold for the Pauli and Dirac particles. ...
IOSR Journal of Electrical and Electronics Engineering (IOSR-JEEE)
... controlled by the two gate potentials applied on either sides of the channel is calculated using the eigenenergies obtained by solving 1D time-independent Schrodinger equation for the potential profile in the channel. The various device characteristics comprising drain characteristics (I D-VDS), tra ...
... controlled by the two gate potentials applied on either sides of the channel is calculated using the eigenenergies obtained by solving 1D time-independent Schrodinger equation for the potential profile in the channel. The various device characteristics comprising drain characteristics (I D-VDS), tra ...
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.