Wigner functions for arbitrary quantum systems
... representation, which preserves the quantum properties of the system in an intuitive way, yet is consistent and comparable with continuous variable cases from quantum optics. In this Letter, based on the original Wigner function for continuous variable systems, we propose an alternative method for c ...
... representation, which preserves the quantum properties of the system in an intuitive way, yet is consistent and comparable with continuous variable cases from quantum optics. In this Letter, based on the original Wigner function for continuous variable systems, we propose an alternative method for c ...
On quantum obfuscation - University of Maryland Institute for
... Encryption of data is fundamental to secure communication in the modern world. Beyond encryption of data lies obfuscation, i.e., encryption of functionality. It is well-known that the most powerful means of obfuscating classical programs, so-called “black-box obfuscation,” is provably impossible [6] ...
... Encryption of data is fundamental to secure communication in the modern world. Beyond encryption of data lies obfuscation, i.e., encryption of functionality. It is well-known that the most powerful means of obfuscating classical programs, so-called “black-box obfuscation,” is provably impossible [6] ...
Advantages of Probability Amplitude Over Probability Density in
... measures photons behind the /4 plate. If observes a photon, he records “1” and if not, he records “0”. As a result obtains data ...
... measures photons behind the /4 plate. If observes a photon, he records “1” and if not, he records “0”. As a result obtains data ...
The New Metaphysics and the Deep Structure of Creativity
... useful to distinguish three forms: 'pre-scientific', 'reductionist', and 'anthropic'. Pre-scientific metaphysics was generally based on incorrect assumptions about the physical world, and is hence excluded from this paper. Reductionist metaphysics include speculations on Newtonian and Darwinian scie ...
... useful to distinguish three forms: 'pre-scientific', 'reductionist', and 'anthropic'. Pre-scientific metaphysics was generally based on incorrect assumptions about the physical world, and is hence excluded from this paper. Reductionist metaphysics include speculations on Newtonian and Darwinian scie ...
ppt - Département de physique
... Theorem: Given q and p : N = pq, then gar-g 0 mod N for at most p+q-1 values of g. We express the maximally mixed state as a mixture of the eigenvalues of UN,a. r 1 d d I 1 j j d j 0 d ...
... Theorem: Given q and p : N = pq, then gar-g 0 mod N for at most p+q-1 values of g. We express the maximally mixed state as a mixture of the eigenvalues of UN,a. r 1 d d I 1 j j d j 0 d ...
Flow of zero-point energy and exploration of phase space in
... performed on a purely classical level ~i.e., \50), while the quantum nature of the system is mimicked through a sampling of the probability distribution of the quantummechanical initial state. As a consequence, quantum fluctuations such as the zero-point energy ~ZPE! are introduced which would vanis ...
... performed on a purely classical level ~i.e., \50), while the quantum nature of the system is mimicked through a sampling of the probability distribution of the quantummechanical initial state. As a consequence, quantum fluctuations such as the zero-point energy ~ZPE! are introduced which would vanis ...
Optimal Large-Scale Quantum State Tomography with Pauli
... example, j = 1 corresponds to `1 = · · · = `b = 0. With the index identification we denote by Bj the Pauli matrix σ `1 ⊗ σ `2 ⊗ · · · ⊗ σ `b , with B1 = Id . We have the following theorem to describe Pauli matrices and represent a density matrix by Pauli matrices. ...
... example, j = 1 corresponds to `1 = · · · = `b = 0. With the index identification we denote by Bj the Pauli matrix σ `1 ⊗ σ `2 ⊗ · · · ⊗ σ `b , with B1 = Id . We have the following theorem to describe Pauli matrices and represent a density matrix by Pauli matrices. ...
Von Neumann algebra automorphisms and time
... The relations between time, gravity, thermodynamics and quantum theory form a cluster of unsolved problems and puzzling surprising theoretical facts. Among these there are the much debated “issue of time” in quantum gravity [1, 2, 3], the lack of a statistical mechanics of general relativity [4], an ...
... The relations between time, gravity, thermodynamics and quantum theory form a cluster of unsolved problems and puzzling surprising theoretical facts. Among these there are the much debated “issue of time” in quantum gravity [1, 2, 3], the lack of a statistical mechanics of general relativity [4], an ...
The powerpoint presentation of the material
... Certain properties of physical objects form complementary pairs. The more accurately one property from a pair is known, the less accurately it is possible, in principle, to know the other. The position & momentum of a particle are a complementary pair of properties: ...
... Certain properties of physical objects form complementary pairs. The more accurately one property from a pair is known, the less accurately it is possible, in principle, to know the other. The position & momentum of a particle are a complementary pair of properties: ...
The powerpoint presentation of the material
... Certain properties of physical objects form complementary pairs. The more accurately one property from a pair is known, the less accurately it is possible, in principle, to know the other. The position & momentum of a particle are a complementary pair of properties: ...
... Certain properties of physical objects form complementary pairs. The more accurately one property from a pair is known, the less accurately it is possible, in principle, to know the other. The position & momentum of a particle are a complementary pair of properties: ...
Quantum Manipulation of Two-Electron Spin States in
... system with a two-pulse procedure: one microsecond pulse that is varied over the dashed green rectangular region depicted in Fig. 2(b) and a fast fixed negative pulse to the gate L of 50 ns duration and of amplitude V ns equal to 80 mV; finally, we proceed to the spin measurement in bringing the sys ...
... system with a two-pulse procedure: one microsecond pulse that is varied over the dashed green rectangular region depicted in Fig. 2(b) and a fast fixed negative pulse to the gate L of 50 ns duration and of amplitude V ns equal to 80 mV; finally, we proceed to the spin measurement in bringing the sys ...
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.