scholarly journals A new epoch of quantum manipulation

2013 ◽  
Vol 1 (1) ◽  
pp. 91-100 ◽  
Author(s):  
Yongjian Han ◽  
Zhen Wang ◽  
Guang-Can Guo
Keyword(s):  
Quantum Mechanics ◽  
Quantum System ◽  
Nobel Prize ◽  
Quantum Computer ◽  
Classical Mechanics ◽  
Quantum Systems ◽  
Microscopic Particle ◽  
Nobel Prize In Physics ◽  
Classical Particles

Abstract The behavior of individual microscopic particles, such as an atom (or a photon), predicted using quantum mechanics, is dramatically different from the behavior of classical particles, such as a planet, determined using classical mechanics. How can the counter-intuitive behavior of the microscopic particle be verified and manipulated experimentally? David Wineland and Serge Haroche, who were awarded the Nobel Prize in physics in 2012, developed a set of methods to isolate the ions and photons from their environment to create a genuine quantum system. Furthermore, they also developed methods to measure and manipulate these quantum systems, which open a path not only to explore the fundamental principles of quantum mechanics, but also to develop a much faster computer: a quantum computer.

scholarly journals Simulating molecules on a cloud-based 5-qubit IBM-Q universal quantum computer

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
S. Leontica ◽  
F. Tennie ◽  
T. Farrow
Keyword(s):  
Quantum System ◽  
Energy Transport ◽  
Quantum Computer ◽  
Complex Molecule ◽  
Dissipative System ◽  
Quantum Simulation ◽  
Quantum Systems ◽  
Molecular Structures ◽  
Unitary Evolution ◽  
Universal Quantum

AbstractSimulating the behaviour of complex quantum systems is impossible on classical supercomputers due to the exponential scaling of the number of quantum states with the number of particles in the simulated system. Quantum computers aim to break through this limit by using one quantum system to simulate another quantum system. Although in their infancy, they are a promising tool for applied fields seeking to simulate quantum interactions in complex atomic and molecular structures. Here, we show an efficient technique for transpiling the unitary evolution of quantum systems into the language of universal quantum computation using the IBM quantum computer and show that it is a viable tool for compiling near-term quantum simulation algorithms. We develop code that decomposes arbitrary 3-qubit gates and implement it in a quantum simulation first for a linear ordered chain to highlight the generality of the approach, and second, for a complex molecule. We choose the Fenna-Matthews-Olsen (FMO) photosynthetic protein because it has a well characterised Hamiltonian and presents a complex dissipative system coupled to a noisy environment that helps to improve the efficiency of energy transport. The method can be implemented in a broad range of molecular and other simulation settings.

Interview with 2012 Nobel Prize Winner Serge Haroche

2013 ◽  
Vol 02 (01) ◽  
pp. 51-53
Keyword(s):  
Nobel Prize ◽  
Quantum Physics ◽  
Annual Report ◽  
Experimental Methods ◽  
Nobel Prize Winner ◽  
Quantum Systems ◽  
Collège De France ◽  
Lecture Series ◽  
National University ◽  
Nobel Prize In Physics

Serge Haroche, Chair in Quantum Physics at the College de France, won a share of the Nobel Prize in Physics 2012. Before the prize was announced, the Centre for Quantum Technologies (CQT) at the National University of Singapore had invited him to contribute to its 2012 annual report. This was after he delivered his prestigious College de France lecture series in Singapore in 2012. The Q&A was published in full on CQT's website and is reproduced here with permission. Serge Haroche was awarded the Nobel Prize in Physics 2012 "for ground-breaking experimental methods that enable measuring and manipulation of individual quantum systems."

scholarly journals Can small quantum systems learn

2017 ◽  
Vol 17 (7&8) ◽  
pp. 568-594
Author(s):  
Nathan Wiebe ◽  
Christopher Grandade
Keyword(s):  
Quantum Mechanics ◽  
Fault Tolerance ◽  
Bayesian Inference ◽  
Quantum System ◽  
Lower Bounds ◽  
State Vector ◽  
Quantum Systems ◽  
Posterior Distributions ◽  
Quantum Devices ◽  
Small Quantum

We examine the question of whether quantum mechanics places limitations on the ability of small quantum devices to learn. We specifically examine the question in the context of Bayesian inference, wherein the prior and posterior distributions are encoded in the quantum state vector. We conclude based on lower bounds from Grover’s search that an efficient blackbox method for updating the distribution is impossible. We then address this by providing a new adaptive form of approximate quantum Bayesian inference that is polynomially faster than its classical anolog and tractable if the quantum system is augmented with classical memory or if the low–order moments of the distribution are protected through redundant preparation. This work suggests that there may be a connection between fault tolerance and the capacity of a quantum system to learn from its surroundings.

Loss and Dissipation: The RLC Circuit

2021 ◽  
pp. 230-246
Author(s):  
Duncan G. Steel
Keyword(s):  
Quantum Mechanics ◽  
Energy Loss ◽  
Quantum System ◽  
Equations Of Motion ◽  
Quantum Systems ◽  
Quantum Vacuum ◽  
Classical Systems ◽  
Rlc Circuit ◽  
Quantum Behavior ◽  
Continuum Of States

The effects of energy loss or dissipation is well-known and understood in classical systems. It is the source of heat in LCR circuits and in the application of brakes in a vehicle or why a struck bell does not ring indefinitely. Understanding quantum behavior begins with understanding the Hamiltonian for the problem. Classically, loss arises from a coupling of the Hamiltonian for an isolated quantum system to a continuum of states. We look at such a Hamiltonian and develop the equations of motion following the rules of quantum mechanics and find that even in a quantum system, this coupling leads to loss and non-conservation of probability in the otherwise isolated quantum system. This is the Weisskopf–Wigner formalism that is then used to understand the quantum LCR circuit. The same formalism is used in Chapter 15 for the decay of isolated quantum systems by coupling to the quantum vacuum and the resulting emission of a photon.

scholarly journals The philosophical foundations of quantum computer modeling

2019 ◽  
Vol 17 (4) ◽  
pp. 85-92
Author(s):  
Anna Yu. Storozhuk
Keyword(s):  
Quantum Mechanics ◽  
Quantum System ◽  
Quantum Computer ◽  
Internal State ◽  
Sufficient Accuracy ◽  
Reduction Wave ◽  
Philosophical Foundations ◽  
Simulated System ◽  
Classical Computer ◽  
Heisenberg's Uncertainty Principle

The source of some problems of the quantum mechanics is the observer’s influence on the system. In particular, such problems include the reduction wave function, which forces physicists to talk about “hidden parameters” and the incompleteness of quantum mechanics. Measurements of a quantum system violate its internal state and make it impossible to obtain information about its other parameters (Heisenberg’s uncertainty principle). In 1980 there appeared the thesis that since modeling the behavior of a quantum system on a classical computer cannot provide sufficient accuracy for reproducing all its parameters, there is a need for a quantum computer. The question arises: to what degree can a quantum computer help to solve traditional epistemological problems of quantum mechanics? Can modelling the behavior of elementary particles on a quantum computer “bypass” the problem of the observer’s influence on the system? In other words, is it possible to obtain information about the behavior of a quantum system without observation? Will the internal state of the simulated system be preserved?

scholarly journals Más allá de la presuposición newtoniana: propiedades genuinamente disposicionales en la mecánica cuántica

1990 ◽  
Vol 22 (66) ◽  
pp. 25-37
Author(s):  
Sergio Martínez
Keyword(s):  
Quantum Mechanics ◽  
Quantum System ◽  
Physical System ◽  
Modern Science ◽  
Quantum Systems ◽  
Theoretical Modeling ◽  
Different Types ◽  
Modern Physics ◽  
Dispositional Properties

A central metaphysical thesis of modern science has been the idea that the structure of a physical system can be explained in terms of the properties of its constitutive subsystems. I call this presupposition the Newtonian merological presupposition. After some brief introductory remarks on the role of this presupposition in the methodology of modern physics, and after mentioning some recent challenges to it, I focus my attention on quantum systems. Quantum mechanics is the only highly confirmed theory in which the Newtonian merological presupposition is denied. I argue that the presence of a non-Newtonian (holistic) merological structure is the result of the existence of two different types of properties, and in particular of the existence of genuinely dispositional properties. Genuinely dispositional properties are properties of a system which are not reducible to occurrent properties of the subsystems. This distinction between two different types of properties can be made precise in a lattice theoretical modeling of the possible properties and states attributable to a quantum system. I conclude by giving an example of the sort of genuinely dispositional properties that are constitutive of quantum systems.

scholarly journals Modelling Wave-Particle Duality of Classical Particles and Waves

2021 ◽  
Author(s):  
Chen Yang ◽  
S. Olutunde Oyadiji
Keyword(s):  
Quantum Mechanics ◽  
Classical Mechanics ◽  
Mathematical Structure ◽  
Momentum Exchange ◽  
The Past ◽  
Wave Particle Duality ◽  
Classical Waves ◽  
Fundamental Phenomenon ◽  
Energy And Momentum ◽  
Classical Particles

Abstract Wave-particle duality is the fundamental phenomenon of particles and fields in quantum mechanics. In the past, the trajectory-like (particle-like) behaviour and wave-like behaviour has been considered separately. In this article, a superimposed model is derived to characterise wave-particle duality of classical particles. The superimposed model reflects an invariant mathematical structure (analogous variables and differential equations) from classical mechanics, classical field theories and quantum mechanics. Its analytical solution carries trajectory-like property (phase-independent) and wave-like property (phase-dependent) of particles that is consistent with to Schrodinger’s picture. Subsequently, the presented model is applied to model duality of classical waves in electromagnetism, acoustics and elasticity. The analysis implies the existence of quantum effects of classical waves at macroscopic scale. It predicts quantum picture on energy and momentum exchange between classical particles and waves. As seen in the model, wave-particle duality reflects inherent and indispensable characteristics of classical objects.

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