Stochastic Schrödinger equations
... system and its environment, the quantized electromagnetic field, is given by unitaries satisfying a quantum stochastic differential equation. Given a measurement of some field observables it is shown how to condition the state of the system on outcomes of the measurement using the construction of se ...
... system and its environment, the quantized electromagnetic field, is given by unitaries satisfying a quantum stochastic differential equation. Given a measurement of some field observables it is shown how to condition the state of the system on outcomes of the measurement using the construction of se ...
The Indivisible Now: why time must be discrete. - Philsci
... considered individually as being determinate. The entangled system for a pair of photons for example is a non-divisible system. Secondly, as previously discussed, time being connected with physical properties implies various properties time itself must have, and in the case of non-reducible properti ...
... considered individually as being determinate. The entangled system for a pair of photons for example is a non-divisible system. Secondly, as previously discussed, time being connected with physical properties implies various properties time itself must have, and in the case of non-reducible properti ...
Hamiltonian Systems with Three or More
... the Baggot Hamiltonian, as β12 < 0 and λ > 0 the 1:1 resonance width actually decreases as the actions I1 , I2 get larger. Note also that we do not explicitly consider secondary resonances since we are interested only in the large-scale structure of the classical phase space (i.e., intersection of t ...
... the Baggot Hamiltonian, as β12 < 0 and λ > 0 the 1:1 resonance width actually decreases as the actions I1 , I2 get larger. Note also that we do not explicitly consider secondary resonances since we are interested only in the large-scale structure of the classical phase space (i.e., intersection of t ...
Quantum Clustering Algorithms - The International Machine
... Multidisciplinary by nature, Quantum Information Processing (QIP) is at the crossroads of computer science, mathematics, physics and engineering. It concerns the implications of quantum mechanics for information processing purposes (Nielsen & Chuang, 2000). Quantum information is very different from ...
... Multidisciplinary by nature, Quantum Information Processing (QIP) is at the crossroads of computer science, mathematics, physics and engineering. It concerns the implications of quantum mechanics for information processing purposes (Nielsen & Chuang, 2000). Quantum information is very different from ...
Presentation
... • When a wave function collapses, it collapses everywhere at once. (nonlocal) • When a physical system is in a state of superposition, it is not in a single well-defined state. (indefinite) • When a system collapses to a single final state among multiple possibilities of a superposition, it does so ...
... • When a wave function collapses, it collapses everywhere at once. (nonlocal) • When a physical system is in a state of superposition, it is not in a single well-defined state. (indefinite) • When a system collapses to a single final state among multiple possibilities of a superposition, it does so ...
The Age of Entanglement Quantum Computing the (Formerly) Uncomputable
... the outcome of experiments performed on particles on the other side of the Universe. Unbelievable! We further assert that a quantum computer can simultaneously compute the answer to a million questions all at the same time, by performing only a single computation. Audacious! These are bold and impla ...
... the outcome of experiments performed on particles on the other side of the Universe. Unbelievable! We further assert that a quantum computer can simultaneously compute the answer to a million questions all at the same time, by performing only a single computation. Audacious! These are bold and impla ...
No-Go Theorem for the Composition of Quantum
... Since association implies tracking, and since the conclusions of PI c and PI c;tr are identical, it follows that if PI c;tr and the antecedent of PI c hold, then PI c also holds. Thus PI c;tr implies PI c , and PI c;tr is sufficient to generate the PBR contradiction. What is the physical rationale f ...
... Since association implies tracking, and since the conclusions of PI c and PI c;tr are identical, it follows that if PI c;tr and the antecedent of PI c hold, then PI c also holds. Thus PI c;tr implies PI c , and PI c;tr is sufficient to generate the PBR contradiction. What is the physical rationale f ...
Maximal attainable boost and energy of elementary particles as a
... This letter presents the scenario establishing the ultimate upper bound on the Lorentz boost and energy of elementary particles with a non-zero mass. The cosmic ray detectors measure higher and higher energies; recently the IceCube collaboration released data containing extra terrestrial neutrino ev ...
... This letter presents the scenario establishing the ultimate upper bound on the Lorentz boost and energy of elementary particles with a non-zero mass. The cosmic ray detectors measure higher and higher energies; recently the IceCube collaboration released data containing extra terrestrial neutrino ev ...
There can be only one
... to measurable mechanical forces4. (As an example, the frequency shift for atoms in a state with principal quantum number 80 at a distance of 5 μm is of the order of a few hundred MHz.) The Rydberg excitation blockade was first observed in ultracold gases5,6, and has been recently demonstrated most s ...
... to measurable mechanical forces4. (As an example, the frequency shift for atoms in a state with principal quantum number 80 at a distance of 5 μm is of the order of a few hundred MHz.) The Rydberg excitation blockade was first observed in ultracold gases5,6, and has been recently demonstrated most s ...
QUANTUM SPIN GLASSES IN FINITE DIMENSIONS
... the z-representaion of the spin operators, which in this case can simply be replaced by their eigenvalues ±1 (after rescaling the couplings) giving exactly the classical P EA-model in d dimensions: H = − hiji Jij Siz Sjz , where now Si = ±1 are Ising spin variables. In this way the transverse field ...
... the z-representaion of the spin operators, which in this case can simply be replaced by their eigenvalues ±1 (after rescaling the couplings) giving exactly the classical P EA-model in d dimensions: H = − hiji Jij Siz Sjz , where now Si = ±1 are Ising spin variables. In this way the transverse field ...
Quantum Darwinism as a Darwinian process - Non
... process responsible for the emergence of classical reality from its quantum substrate. This theory explains information transfer between the quantum and classical realm during the process of decoherence as involving a ‘copy with selective retention’ mechanism characteristic of Darwinian processes. Q ...
... process responsible for the emergence of classical reality from its quantum substrate. This theory explains information transfer between the quantum and classical realm during the process of decoherence as involving a ‘copy with selective retention’ mechanism characteristic of Darwinian processes. Q ...
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.