PDF ∗ , 88K - UCLA Chemistry and Biochemistry
... x ) a, b and G(E) ) (E - H + iW)-1 is the total Green’s function for this system. Note that W is the total imaginary potential in all asymptotes. This theory is very flexible and easy to implement in many types of electronic structure calculations. It is based on two powerful methods of quantum reac ...
... x ) a, b and G(E) ) (E - H + iW)-1 is the total Green’s function for this system. Note that W is the total imaginary potential in all asymptotes. This theory is very flexible and easy to implement in many types of electronic structure calculations. It is based on two powerful methods of quantum reac ...
Why physics does not preclude free will
... ‘empty’ pending a measurement result; measurements bring about certain aspects of the past. However, arguably this picture is not consistent with the TSVF, since it treats an emitted quantum as existing for some time without a post-selection measurement; i.e., as a single forward-directed state (off ...
... ‘empty’ pending a measurement result; measurements bring about certain aspects of the past. However, arguably this picture is not consistent with the TSVF, since it treats an emitted quantum as existing for some time without a post-selection measurement; i.e., as a single forward-directed state (off ...
Finite Two-Dimensional Systems of Electrons at Zero and Finite
... we investigate the possibility of classical simulations of quantum systems via the method of mapping. We take two-dimensional systems of electrons as the target of our analyses. They are one of indispensable elements of semiconductor electronic devices and their properties not only in the bulk but a ...
... we investigate the possibility of classical simulations of quantum systems via the method of mapping. We take two-dimensional systems of electrons as the target of our analyses. They are one of indispensable elements of semiconductor electronic devices and their properties not only in the bulk but a ...
Get PDF - OSA Publishing
... Y numerically. One can identify that the intersections of X and Y are the zeros of R. However, for the case of K = k0 , R is not zero, but unity. This is because for this particular choice, the denominator of R is also zero. Therefore, one can not determine R only from the numerator. The limit of R ...
... Y numerically. One can identify that the intersections of X and Y are the zeros of R. However, for the case of K = k0 , R is not zero, but unity. This is because for this particular choice, the denominator of R is also zero. Therefore, one can not determine R only from the numerator. The limit of R ...
Wave transport and statistical properties of an time symmetry
... The outline of the article is as follows. In Sec. II we summarize quantum mechanics with complex potentials and at the same time put our model into the general framework of PT invariance. In the same section we also discuss how a particular device should be designed to ensure PT symmetry and thereby ...
... The outline of the article is as follows. In Sec. II we summarize quantum mechanics with complex potentials and at the same time put our model into the general framework of PT invariance. In the same section we also discuss how a particular device should be designed to ensure PT symmetry and thereby ...
Beam Splitter Input
... The Mach-Zehnder interferometer is a very interesting apparatus. It is extensively studied, because of its strange quantum mechanical properties. It represents the 2-mode equivalent of Young’s continuous-mode double slit interferometer. It is well known that welcher-weg or which-path knowledge about ...
... The Mach-Zehnder interferometer is a very interesting apparatus. It is extensively studied, because of its strange quantum mechanical properties. It represents the 2-mode equivalent of Young’s continuous-mode double slit interferometer. It is well known that welcher-weg or which-path knowledge about ...
Part III
... is a projector onto correlated (entangled) states of the system and ancilla. The generalised measurement is a von Neumann measurement in which the system and ancilla are compared. ...
... is a projector onto correlated (entangled) states of the system and ancilla. The generalised measurement is a von Neumann measurement in which the system and ancilla are compared. ...
Unified Treatment of Quantum Fluctuation Theorem and Jarzynski
... ρ(0) and ρ(T ) respectively. For example, when the system is in equilibrium at initial and final time and we choose  and B̂ as Hamiltonian, this condition is satisfied. We treat this case in the section V. In such cases, ∆S is considered as entropy production in the sense of [1], namely ∆S ≡ −kB l ...
... ρ(0) and ρ(T ) respectively. For example, when the system is in equilibrium at initial and final time and we choose  and B̂ as Hamiltonian, this condition is satisfied. We treat this case in the section V. In such cases, ∆S is considered as entropy production in the sense of [1], namely ∆S ≡ −kB l ...
Diverging equilibration times in long
... Equilibration is one of the central concepts of thermodynamics, but our understanding of the underlying microscopic processes is still far from complete. Studies of the approach to equilibrium can be traced back to Boltzmann’s work [1] in the early days of statistical mechanics, and they are also cl ...
... Equilibration is one of the central concepts of thermodynamics, but our understanding of the underlying microscopic processes is still far from complete. Studies of the approach to equilibrium can be traced back to Boltzmann’s work [1] in the early days of statistical mechanics, and they are also cl ...
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.