Paper
... light resonant with the 5S1=2 j2; 1i ! 5P3=2 j3; 1i transition. The 362 nK energy from a single photon recoil distinguished scattered atoms from the subrecoil 15 nK energy range of the condensate atoms. Successive scatterings would eject measured atoms from the trap. After each QZE experiment ...
... light resonant with the 5S1=2 j2; 1i ! 5P3=2 j3; 1i transition. The 362 nK energy from a single photon recoil distinguished scattered atoms from the subrecoil 15 nK energy range of the condensate atoms. Successive scatterings would eject measured atoms from the trap. After each QZE experiment ...
A quantum computing primer for operator theorists
... fields promise far reaching applications [12,24,41,60], there are still many theoretical and experimental issues that must be overcome, and many involve deep mathematical problems. The main goal of this paper is to provide a primer on some of the basic aspects of quantum computing for researchers wi ...
... fields promise far reaching applications [12,24,41,60], there are still many theoretical and experimental issues that must be overcome, and many involve deep mathematical problems. The main goal of this paper is to provide a primer on some of the basic aspects of quantum computing for researchers wi ...
Generation of mesoscopic superpositions of two
... The scheme of the linear trap used in the Innsbruck group: A radio-frequency field (16 MHz, about 1000 Volts) is applied to the elongated electrodes (red) to provide the trapping in the radial direction. The ring-shaped electrodes at the two ends are responsible for the trapping in the axial directi ...
... The scheme of the linear trap used in the Innsbruck group: A radio-frequency field (16 MHz, about 1000 Volts) is applied to the elongated electrodes (red) to provide the trapping in the radial direction. The ring-shaped electrodes at the two ends are responsible for the trapping in the axial directi ...
Synchronistic Phenomena as Entanglement
... entanglement correlations. A composite quantum system in a so-called entangled state will show correlations between the results of measurements of observables which pertain to its components. A simple standard example is a system of two particles of spin 1/2 in a singlet or triplet state, which show ...
... entanglement correlations. A composite quantum system in a so-called entangled state will show correlations between the results of measurements of observables which pertain to its components. A simple standard example is a system of two particles of spin 1/2 in a singlet or triplet state, which show ...
Lieb-Robinson Bounds and the Speed of Light from
... taking this principle seriously: if object A causes a change on object B, there must be changes involving the points in between. The field is exactly what changes. In addition, if something is ‘‘happening’’ at all the intermediate points, then the interaction between the objects must propagate with ...
... taking this principle seriously: if object A causes a change on object B, there must be changes involving the points in between. The field is exactly what changes. In addition, if something is ‘‘happening’’ at all the intermediate points, then the interaction between the objects must propagate with ...
Hot gases: The transition from the line spectra to
... article.2 Although I agree with parts of his criticism, I cannot follow all of his arguments. I agree that my approach of using a simple two-level system was oversimplified and that a proper application of Einstein’s derivation is not possible if only a two-level system with well-defined energies is ...
... article.2 Although I agree with parts of his criticism, I cannot follow all of his arguments. I agree that my approach of using a simple two-level system was oversimplified and that a proper application of Einstein’s derivation is not possible if only a two-level system with well-defined energies is ...
BASIC IDEAS of QUANTUM MECHANICS I. QUANTUM STATES
... assumption that it is possible to reduce the entire description of a physical system to a specification of its microscopic ”variables”, and the way that these influence each other (ie., ’interact with’ each other). Another name for ’variables’ is ’coordinates’. Both of these terms simply refer to th ...
... assumption that it is possible to reduce the entire description of a physical system to a specification of its microscopic ”variables”, and the way that these influence each other (ie., ’interact with’ each other). Another name for ’variables’ is ’coordinates’. Both of these terms simply refer to th ...
Evade the Heisenberg Uncertainty Principle
... determine the quantum state without the need for post-processing. However, that novel method had a major drawback: It uses minimally disturbing measurements, so-called weak measurements, to determine the system's quantum state. The basic idea behind weak measurements is to gain very little informati ...
... determine the quantum state without the need for post-processing. However, that novel method had a major drawback: It uses minimally disturbing measurements, so-called weak measurements, to determine the system's quantum state. The basic idea behind weak measurements is to gain very little informati ...
Effective Constraints of - Institute for Gravitation and the Cosmos
... 1. There is a consistent set of corrected constraints which are first class. 2. Cosmology: • can formulate equations of motion in terms of gauge invariant variables. • potentially observable predictions. 3. Indications that quantization ambiguities are ...
... 1. There is a consistent set of corrected constraints which are first class. 2. Cosmology: • can formulate equations of motion in terms of gauge invariant variables. • potentially observable predictions. 3. Indications that quantization ambiguities are ...
Asymptotics and 6j-symbols 1 Introduction
... The correspondence between Kähler manifolds and representations is very helpful in understanding invariant theory for Lie groups. There are three essential ideas: first, the above association between irreps and integral coadjoint orbits; second, that tensor products of representations correspond to ...
... The correspondence between Kähler manifolds and representations is very helpful in understanding invariant theory for Lie groups. There are three essential ideas: first, the above association between irreps and integral coadjoint orbits; second, that tensor products of representations correspond to ...
A REPORT ON QUANTUM COMPUTING
... Research must devise a way to maintain decoherence and other potential sources of error at an acceptable level. Probably the most important idea in this field is the application of error correction in phase coherence as a means to extract information and reduce error in a quantum system without actu ...
... Research must devise a way to maintain decoherence and other potential sources of error at an acceptable level. Probably the most important idea in this field is the application of error correction in phase coherence as a means to extract information and reduce error in a quantum system without actu ...
THE DETERMINATION OF PHOTON MASS
... The question of whether particles of light have mass has been asked in natural philosophy for centuries, starting with theories such as the corpuscular theory of Newton and contemporaries, based in turn on older ideas back to classical times. In the early twentieth century, Planck and Einstein intro ...
... The question of whether particles of light have mass has been asked in natural philosophy for centuries, starting with theories such as the corpuscular theory of Newton and contemporaries, based in turn on older ideas back to classical times. In the early twentieth century, Planck and Einstein intro ...
Permanent Uncertainty: On the Quantum evaluation of the determinant and permanent of a matrix
... the permutations of 1 : : : n [2]. The determinant is de ned by the same sum of the permutations, where in addition each odd permutation is taken with a negative sign. Permanents occur naturally in various counting problems in combinatorics[4], graph theory[1], and logic. If there was a way to evalu ...
... the permutations of 1 : : : n [2]. The determinant is de ned by the same sum of the permutations, where in addition each odd permutation is taken with a negative sign. Permanents occur naturally in various counting problems in combinatorics[4], graph theory[1], and logic. If there was a way to evalu ...
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.