Spins in quantum dots: Hyperfine interaction, transport, and
... R time-ordering operator. If the exchange is pulsed on for a time τs such that J(t)dt/~ = J0 τs /~ = π, the states of the two spins, with associated operators SL and SR , will be exchanged. This is the swap operation. Pulsing the exchange for the shorter time τs /2 generates the “square-root of swap ...
... R time-ordering operator. If the exchange is pulsed on for a time τs such that J(t)dt/~ = J0 τs /~ = π, the states of the two spins, with associated operators SL and SR , will be exchanged. This is the swap operation. Pulsing the exchange for the shorter time τs /2 generates the “square-root of swap ...
Towards a microscopic Description of classical Solutions in Field
... nature is fundamentally quantum. In this thesis we want to take this perspective as a starting point and investigate its consequences. From this point of view, every classical object should be understood as a quantum bound state of proper microscopic degrees of freedom. As a consequence, consistency ...
... nature is fundamentally quantum. In this thesis we want to take this perspective as a starting point and investigate its consequences. From this point of view, every classical object should be understood as a quantum bound state of proper microscopic degrees of freedom. As a consequence, consistency ...
New efficient integral algorithms for quantum chemistry
... Quantum chemistry is the application of quantum physics to the study of chemical systems. The underlying theoretical framework -quantum theory- tends to be very counterintuitive to many scientists, yet it is the single most successful theory in the history of science. Its success lies in great measu ...
... Quantum chemistry is the application of quantum physics to the study of chemical systems. The underlying theoretical framework -quantum theory- tends to be very counterintuitive to many scientists, yet it is the single most successful theory in the history of science. Its success lies in great measu ...
Genuine Fortuitousness
... epistemological or subjective uncertainty about the world but rather reveals the world as it truly is. The uncertainty of certain physical variables under various conditions is an objective fact about the universe and must be treated as such. Copenhagen’s treatment of uncertainty stands in stark con ...
... epistemological or subjective uncertainty about the world but rather reveals the world as it truly is. The uncertainty of certain physical variables under various conditions is an objective fact about the universe and must be treated as such. Copenhagen’s treatment of uncertainty stands in stark con ...
A neutral atom quantum register
... In the past century, research in quantum mechanics was initially focussed on the theoretical exploration and later on the experimental investigation of quantum effects. At the beginning of the 21st century, the field of “quantum engineering”, i. e. the experimental control of individual quantum syst ...
... In the past century, research in quantum mechanics was initially focussed on the theoretical exploration and later on the experimental investigation of quantum effects. At the beginning of the 21st century, the field of “quantum engineering”, i. e. the experimental control of individual quantum syst ...
Current Fluctuations in Hybrid-Superconductor Normal Structures
... dip at a frequency corresponding to the energy splitting of the Andreev bound states which is a signature of the coherent exchange of Cooper pairs between the quantum dot and the superconductor. Furthermore, in the high frequency regime, the so called quantum noise regime, the noise spectrum exhibi ...
... dip at a frequency corresponding to the energy splitting of the Andreev bound states which is a signature of the coherent exchange of Cooper pairs between the quantum dot and the superconductor. Furthermore, in the high frequency regime, the so called quantum noise regime, the noise spectrum exhibi ...
Matrix Mechanics and Wave Mechanics - Philsci
... empirical equivalence. Schrödinger’s early wave-mechanical treatment of the atom as a charge cloud (instead of an electron as a particle, orbiting around the nucleus – Bohr’s early model) did not at first accurately account for radiation of the atom (while Bohr’s model did), given that only certain ...
... empirical equivalence. Schrödinger’s early wave-mechanical treatment of the atom as a charge cloud (instead of an electron as a particle, orbiting around the nucleus – Bohr’s early model) did not at first accurately account for radiation of the atom (while Bohr’s model did), given that only certain ...
The Emperor`s New Mind by Roger Penrose
... series? What is the survival value that evolution found in producing consciousness? Is there a level beyond quantum mechanics in which the direction of time and the distinction between right and left are firmly embedded? Are the laws of quantum mechanics, perhaps even deeper laws, essential for the ...
... series? What is the survival value that evolution found in producing consciousness? Is there a level beyond quantum mechanics in which the direction of time and the distinction between right and left are firmly embedded? Are the laws of quantum mechanics, perhaps even deeper laws, essential for the ...
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.