Quantum Chaos and Quantum Computers
... spins (see recent review [2] and references there in). The computer operation is based on a controlled series of two-qubit coupling switches, on and o¡ which together with one-qubit rotations allow to realize any unitary operation in the Hilbert space of size NH 2n [3,4]. In this respect the inter ...
... spins (see recent review [2] and references there in). The computer operation is based on a controlled series of two-qubit coupling switches, on and o¡ which together with one-qubit rotations allow to realize any unitary operation in the Hilbert space of size NH 2n [3,4]. In this respect the inter ...
Model Visualization of Atomic Quantum Numbers Three
... case we can think of the four quantum numbers as the "address" of electrons in atoms. There are three rules or principles that should be considered in the determination of the electron configuration of an atom, and this principle applies to a variety of elements are: 1) Prohibition of the Pauli prin ...
... case we can think of the four quantum numbers as the "address" of electrons in atoms. There are three rules or principles that should be considered in the determination of the electron configuration of an atom, and this principle applies to a variety of elements are: 1) Prohibition of the Pauli prin ...
Is Classical Statistical Mechanics Self-Consistent? (A paper in honor of C. F. von Weizsäcker, 1912–2007)
... three-men-circle, with certainty not to make the bomb. Just as little, there was no passion to make the bomb . . . ” (cited from: C. F. von Weizsäcker, letter to Mark Walker, August 5, 1990). The truth about this question was not revealed until 1993, when transcripts of secretly recorded conversati ...
... three-men-circle, with certainty not to make the bomb. Just as little, there was no passion to make the bomb . . . ” (cited from: C. F. von Weizsäcker, letter to Mark Walker, August 5, 1990). The truth about this question was not revealed until 1993, when transcripts of secretly recorded conversati ...
92 - UCSB Physics - University of California, Santa Barbara
... explanation cosmology has usually traced to the intitial condition. These include the approximate homogeneity and In a fundamental formulation of the quantum mechanics of a closed system, such as the universe as a whole, three forms of information are needed to isotropy, the approximate spatial flat ...
... explanation cosmology has usually traced to the intitial condition. These include the approximate homogeneity and In a fundamental formulation of the quantum mechanics of a closed system, such as the universe as a whole, three forms of information are needed to isotropy, the approximate spatial flat ...
Lecture 18 — October 26, 2015 1 Overview 2 Quantum Entropy
... informational standpoint. The informational statement is that we can sometimes be more certain about the joint state of a quantum system than we can be about any one of its individual parts, and this is the reason that conditional quantum entropy can be negative. This is in fact the same observation ...
... informational standpoint. The informational statement is that we can sometimes be more certain about the joint state of a quantum system than we can be about any one of its individual parts, and this is the reason that conditional quantum entropy can be negative. This is in fact the same observation ...
The 1908 Tunguska cosmic body (TCB) explosion: Role of hydrogen thermonuclear
... this plasma is not expected to be the Maxwell-Boltzmann distribution. It is shown that the use of a generalized momentum distribution leads to substantial increases of deuteron fusion rates and that a thermonuclear explosion may compete with a thermo-chemical explosion. Therefore, it may be possible ...
... this plasma is not expected to be the Maxwell-Boltzmann distribution. It is shown that the use of a generalized momentum distribution leads to substantial increases of deuteron fusion rates and that a thermonuclear explosion may compete with a thermo-chemical explosion. Therefore, it may be possible ...
Population inversion in quantum dot ensembles via adiabatic rapid passage
... inhomogeneity in practical realizations of ensembles of dots means that no resonant pulse can invert an entire ensemble exhibiting wide variation in energy and coupling strength. There is nevertheless a very good prospect for such inversion via adiabatic rapid passage 共ARP兲, which is known to be rob ...
... inhomogeneity in practical realizations of ensembles of dots means that no resonant pulse can invert an entire ensemble exhibiting wide variation in energy and coupling strength. There is nevertheless a very good prospect for such inversion via adiabatic rapid passage 共ARP兲, which is known to be rob ...
A hands-on introduction to single photons and quantum mechanics for undergraduates
... with our students, introducing concepts as needed to explain observed results. Most of the experiments described have been performed by others in both pedagogical and research settings. The goal of this paper is to offer a slightly different pedagogical approach than previously reported and to clari ...
... with our students, introducing concepts as needed to explain observed results. Most of the experiments described have been performed by others in both pedagogical and research settings. The goal of this paper is to offer a slightly different pedagogical approach than previously reported and to clari ...
Wormholes and Entanglement
... Fake entanglement requires more than the fact that a pair of systems are currently in a state which lies in a particular subspace. For example, consider a pair of entangled photons produced by the annihilation of an electron and a positron with total momentum zero. The joint state of the photons lie ...
... Fake entanglement requires more than the fact that a pair of systems are currently in a state which lies in a particular subspace. For example, consider a pair of entangled photons produced by the annihilation of an electron and a positron with total momentum zero. The joint state of the photons lie ...
PDF Version - Physics (APS)
... conducting states. Moreover, the conducting states are real and can be measured, and in the case of the quantum spin Hall state, are naturally spin polarized, which can have interesting applications in spintronics. What’s special about the surface of Bi1− x Sbx that it has these properties? It turns ...
... conducting states. Moreover, the conducting states are real and can be measured, and in the case of the quantum spin Hall state, are naturally spin polarized, which can have interesting applications in spintronics. What’s special about the surface of Bi1− x Sbx that it has these properties? It turns ...
Coupled Quantum– Atomistic and Quantum–Continuum Mechanics
... model. The basic idea is to produce an analytical expression for the potential energy surface, whose parameters are fit to data obtained from ab initio calculations, in distinct contrast to the empirical approach of using experimental material properties. Experimental observables represent a thermal ...
... model. The basic idea is to produce an analytical expression for the potential energy surface, whose parameters are fit to data obtained from ab initio calculations, in distinct contrast to the empirical approach of using experimental material properties. Experimental observables represent a thermal ...
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.