Read by QxMD icon Read

Quantum mechanics complementary principle

R Barends, A Shabani, L Lamata, J Kelly, A Mezzacapo, U Las Heras, R Babbush, A G Fowler, B Campbell, Yu Chen, Z Chen, B Chiaro, A Dunsworth, E Jeffrey, E Lucero, A Megrant, J Y Mutus, M Neeley, C Neill, P J J O'Malley, C Quintana, P Roushan, D Sank, A Vainsencher, J Wenner, T C White, E Solano, H Neven, John M Martinis
Quantum mechanics can help to solve complex problems in physics and chemistry, provided they can be programmed in a physical device. In adiabatic quantum computing, a system is slowly evolved from the ground state of a simple initial Hamiltonian to a final Hamiltonian that encodes a computational problem. The appeal of this approach lies in the combination of simplicity and generality; in principle, any problem can be encoded. In practice, applications are restricted by limited connectivity, available interactions and noise...
June 9, 2016: Nature
Mark S Hybertsen, Latha Venkataraman
Over the past 10 years, there has been tremendous progress in the measurement, modeling and understanding of structure-function relationships in single molecule junctions. Numerous research groups have addressed significant scientific questions, directed both to conductance phenomena at the single molecule level and to the fundamental chemistry that controls junction functionality. Many different functionalities have been demonstrated, including single-molecule diodes, optically and mechanically activated switches, and, significantly, physical phenomena with no classical analogues, such as those based on quantum interference effects...
March 15, 2016: Accounts of Chemical Research
S T Bromley, T P M Goumans, E Herbst, A P Jones, B Slater
Studies aiming to understand the physicochemical properties of interstellar dust and the chemical reactions that occur on and in it have traditionally been the preserve of astronomical observation and experimental attempts to mimic astronomically relevant conditions in the laboratory. Increasingly, computational modelling in its various guises is establishing a complementary third pillar of support to this endeavour by providing detailed insights into the complexities of interstellar dust chemistry. Inherently, the basis of computational modelling is to be found in the details (e...
September 21, 2014: Physical Chemistry Chemical Physics: PCCP
Toshihiko Sasaki, Yoshihisa Yamamoto, Masato Koashi
Quantum cryptography exploits the fundamental laws of quantum mechanics to provide a secure way to exchange private information. Such an exchange requires a common random bit sequence, called a key, to be shared secretly between the sender and the receiver. The basic idea behind quantum key distribution (QKD) has widely been understood as the property that any attempt to distinguish encoded quantum states causes a disturbance in the signal. As a result, implementation of a QKD protocol involves an estimation of the experimental parameters influenced by the eavesdropper's intervention, which is achieved by randomly sampling the signal...
May 22, 2014: Nature
Chunying Chen, Yu-Feng Li, Ying Qu, Zhifang Chai, Yuliang Zhao
Manufactured nanomaterials with novel physicochemical properties are an important basis for nanosciences and related technologies. Nanotoxicology, aiming to understand the principles of interactions at the nano-bio interface and the relationship between the physicochemical properties of nanomaterials and their toxicological profiles, has become a new frontier in nanoscience. Nearly one decade of nanotoxicology research has shown that the interactions between nanomaterials and proteins, cells, animals, humans and the environment as well as the underlying mechanisms of toxicity for nanomaterials are remarkably complicated, requiring dedicated analytical methodology and tools...
November 7, 2013: Chemical Society Reviews
Christian Schnaars, Martin Hennum, Tore Bonge-Hansen
Three new protocols for the nucleophilic halogenations of diazoesters, diazophosphonates, and diazopiperidinylamides as complementary methods to our previously reported electrophilic halogenations are presented for the first time. On the basis of hypervalent α-aryliodonio diazo triflate salts 1A, 2A, and 3A, the corresponding halodiazo compounds are generated via nucleophilic halogenations with tetrabutylammonium halides or potassium halides. The products from subsequent catalytic intermolecular cyclopropanations of the halodiazoesters and halodiazophosphonates and thermal intramolecular C-H insertion of the brominated diazopiperidinylamide are obtained in moderate to good yields after two steps...
August 2, 2013: Journal of Organic Chemistry
Ralf Menzel, Dirk Puhlmann, Axel Heuer, Wolfgang P Schleich
The precise knowledge of one of two complementary experimental outcomes prevents us from obtaining complete information about the other one. This formulation of Niels Bohr's principle of complementarity when applied to the paradigm of wave-particle dualism--that is, to Young's double-slit experiment--implies that the information about the slit through which a quantum particle has passed erases interference. In the present paper we report a double-slit experiment using two photons created by spontaneous parametric down-conversion where we observe interference in the signal photon despite the fact that we have located it in one of the slits due to its entanglement with the idler photon...
June 12, 2012: Proceedings of the National Academy of Sciences of the United States of America
Radu Ionicioiu, Daniel R Terno
Gedanken experiments help to reconcile our classical intuition with quantum mechanics and nowadays are routinely performed in the laboratory. An important open question is the quantum behavior of the controlling devices in such experiments. We propose a framework to analyze quantum-controlled experiments and illustrate it by discussing a quantum version of Wheeler's delayed-choice experiment. Using a quantum control has several consequences. First, it enables us to measure complementary phenomena with a single experimental setup, pointing to a redefinition of complementarity principle...
December 2, 2011: Physical Review Letters
Masaki Nishizaka, Tadashi Mori, Yoshihisa Inoue
The circular dichroism (CD) spectra of (R)-2,2'-dimethoxy-1,1'-binaphthyl (DD) and its untethered and tethered donor-acceptor analogues (DA and DA7-DA9) were investigated experimentally and theoretically. The experimental CD spectra of DD and DA resembled each other in several aspects, displaying a positive-positive-negative Cotton effect pattern in the (1)L(b)-(1)L(a) region and a strong negative couplet at the (1)B(b) band, but significantly differed in transition energy and rotatory strength. The couplet amplitude (A) of the main band was 1...
June 2, 2011: Journal of Physical Chemistry. A
David A Engstrøm, Ja Scott Kelso
Niels Bohr's maxim contraria sunt complementa indicated his strong suspicion that the complementarity interpretation of quantum mechanics might someday be expanded into a generalized principle. It now appears that such a principle has been found in metastability which appears at the scale of living things. Metastability has been proposed as a principle of brain~behavior, and is captured in the extended or 'broken-symmetry' version of the HKB model of coordination dynamics. The metastable regime of coordination dynamics reconciles the tendency of specialized brain regions to express autonomy (segregation) and their simultaneous tendency to work together as a synergetic whole (integration)...
2008: Gestalt Theory
Richard F W Bader
There are two schools of thought in chemistry: one derived from the valence bond and molecular orbital models of bonding, the other appealing directly to the measurable electron density and the quantum mechanical theorems that determine its behavior, an approach embodied in the quantum theory of atoms in molecules, QTAIM. No one questions the validity of the former approach, and indeed molecular orbital models and QTAIM play complementary roles, the models finding expression in the principles of physics. However, some orbital proponents step beyond the models to impose their personal stamp on their use in interpretive chemistry, by denying the possible existence of a physical basis for the concepts of chemistry...
July 22, 2010: Journal of Physical Chemistry. A
Giuseppe Damiani
Darwinian theory, like classic physics, is an incomplete oversimplification of the most complex aspects of the reality. According to the complementarity principle of Taoism and quantum physics, a Lotka-Volterra oscillation between catabolic-entropic and anabolic-syntropic processes might generate the emergence of collective behaviours and fractal structures near the critical points in many physical and biological systems. The proposed mechanism, named metabolic hypercycle, explains many evolutionary dynamics with two alternate and complementary phases at the levels of molecules, cells, organisms, and populations...
September 2007: Rivista di Biologia
Jennifer R Calhoun, Weixia Liu, Katrin Spiegel, Matteo Dal Peraro, Michael L Klein, Kathleen G Valentine, A Joshua Wand, William F DeGrado
We report the solution NMR structure of a designed dimetal-binding protein, di-Zn(II) DFsc, along with a secondary refinement step employing molecular dynamics techniques. Calculation of the initial NMR structural ensemble by standard methods led to distortions in the metal-ligand geometries at the active site. Unrestrained molecular dynamics using a nonbonded force field for the metal shell, followed by quantum mechanical/molecular mechanical dynamics of DFsc, were used to relax local frustrations at the dimetal site that were apparent in the initial NMR structure and provide a more realistic description of the structure...
February 2008: Structure
Lionel R Milgrom
As a therapeutic intervention, homeopathy is the target of increased scepticism because in the main, its remedies are diluted and succussed (potentized) out of material existence. This puts homeopathy seemingly at odds with the paradigm of conventional science, in particular, that atoms and molecules are the fundamental building blocks of all matter. Accordingly, homeopathy cannot work, so that any reported beneficial effects must, at best, be due to the placebo effect. The purpose of this article is to challenge that conclusion and to suggest that there may well be conventional science-based explanations of how homeopathy could be possible...
September 2006: Journal of the Royal Society for the Promotion of Health
Ibrahim Yildiz, Massimiliano Tomasulo, Françisco M Raymo
Semiconductor quantum dots are becoming valuable analytical tools for biomedical applications. Indeed, their unique photophysical properties offer the opportunity to design luminescent probes for imaging and sensing with unprecedented performance. In this context, we have identified operating principles to transduce the supramolecular association of complementary receptor-substrate pairs into an enhancement in the luminescence of sensitive quantum dots. Our mechanism is based on the electrostatic adsorption of cationic quenchers on the surface of anionic quantum dots...
August 1, 2006: Proceedings of the National Academy of Sciences of the United States of America
Katherine Noyes Rogstad, Yun Hee Jang, Lawrence C Sowers, William A Goddard
The accurate replication of DNA requires the formation of complementary hydrogen bonds between a template base and the base moiety of an incoming deoxynucleotide-5'-triphosphate. Recent structural studies suggest that some DNA polymerases contribute additional constraints by interrogating the minor groove face of the incoming and template bases. Therefore, the hydrogen bond-donating or -accepting properties of the base pairing as well as minor groove faces of the bases could be important determinants of correct base selection...
November 2003: Chemical Research in Toxicology
H Walach
Homeopathy is scientifically banned, both for lack of consistent empirical findings, but more so for lack of a sound theoretical model to explain its purported effects. This paper makes an attempt to introduce an explanatory idea based on a generalized version of quantum mechanics (QM), the weak quantum theory (WQT). WQT uses the algebraic formalism of QM proper, but drops some restrictions and definitions typical for QM. This results in a general axiomatic framework similar to QM, but more generalized and applicable to all possible systems...
August 2003: Research in Complementary and Natural Classical Medicine
W J Meggs
In biological systems, complex molecules interact with specificity and rapidity. The hypothesis is advanced that there are complementary sites on the surfaces of pairs of biological molecules with an enhanced attraction due to quantum mechanics. I postulate that a biological homing effect arises from the quantum mechanical probability that complementary pairs of molecules will join, and that this phenomenon is the force that drives biology and gives rise to the existence of life. To illustrate the approach, a simplified calculation is given for the interaction cross-section between two molecules, each with N surface charges that have an identical spatial distribution but with paired charges having opposite signs...
December 1998: Medical Hypotheses
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"