scholarly journals Probabilities and Epistemic Operations in the Logics of Quantum Computation

Entropy ◽  
2018 ◽  
Vol 20 (11) ◽  
pp. 837 ◽  
Author(s):  
Maria Dalla Chiara ◽  
Hector Freytes ◽  
Roberto Giuntini ◽  
Roberto Leporini ◽  
Giuseppe Sergioli
Keyword(s):  
Quantum Information ◽  
Quantum Computation ◽  
Transition Probability ◽  
Quantum Probability ◽  
Quantum States ◽  
Quantum Version ◽  
Logical Connectives ◽  
Quantum Computational Logics ◽  
Absolute Concept ◽  
Relative Concept

Quantum computation theory has inspired new forms of quantum logic, called quantum computational logics, where formulas are supposed to denote pieces of quantum information, while logical connectives are interpreted as special examples of quantum logical gates. The most natural semantics for these logics is a form of holistic semantics, where meanings behave in a contextual way. In this framework, the concept of quantum probability can assume different forms. We distinguish an absolute concept of probability, based on the idea of quantum truth, from a relative concept of probability (a form of transition-probability, connected with the notion of fidelity between quantum states). Quantum information has brought about some intriguing epistemic situations. A typical example is represented by teleportation-experiments. In some previous works we have studied a quantum version of the epistemic operations “to know”, “to believe”, “to understand”. In this article, we investigate another epistemic operation (which is informally used in a number of interesting quantum situations): the operation “being probabilistically informed”.

scholarly journals Holistic logical arguments in quantum computation

2016 ◽  
Vol 66 (2) ◽  
Author(s):  
Maria Luisa Dalla Chiara ◽  
Roberto Giuntini ◽  
Roberto Leporini ◽  
Giuseppe Sergioli
Keyword(s):  
Quantum Information ◽  
Quantum Computation ◽  
Essential Role ◽  
Circuit Theory ◽  
Logical Connectives ◽  
Quantum Computational Logics

AbstractQuantum computational logics represent a logical abstraction from the circuit-theory in quantum computation. In these logics formulas are supposed to denote pieces of quantum information (qubits, quregisters or mixtures of quregisters), while logical connectives correspond to (quantum logical) gates that transform quantum information in a reversible way. The characteristic holistic features of the quantum theoretic formalism (which play an essential role in entanglement-phenomena) can be used in order to develop a

QUANTUM COMPUTATIONAL FINITE-VALUED LOGICS

2007 ◽  
Vol 05 (05) ◽  
pp. 641-665 ◽  
Author(s):  
CESARINO BERTINI ◽  
ROBERTO LEPORINI
Keyword(s):  
Quantum Information ◽  
Quantum Computation ◽  
Quantum Logic ◽  
Physical Models ◽  
Information Quantity ◽  
Logical Operations ◽  
Logical Connectives ◽  
Quantum Computational Logics ◽  
Basic Semantic

The theory of logical gates in quantum computation has suggested new forms of quantum logic, called quantum computational logics. The basic semantic idea is the following: the meaning of a sentence is identified with a quantum information quantity, represented by a quregister (a system of qudits) or, more generally, by a mixture of quregisters (called qumix), whose dimension depends on the logical complexity of the sentence. At the same time, the logical connectives are interpreted as logical operations defined in terms of quantum logical gates. Physical models of quantum computational logics can be built by means of Mach-Zehnder interferometers.

scholarly journals Obscure Qubits and Membership Amplitudes

2021 ◽  
Author(s):  
Steven Duplij ◽  
Raimund Vogl
Keyword(s):  
Hilbert Space ◽  
Quantum Computing ◽  
Density Matrix ◽  
Tensor Product ◽  
Quantum Computation ◽  
Membership Function ◽  
Quantum Probability ◽  
Quantum States ◽  
Born Rule ◽  
Quantum Amplitude

We propose a concept of quantum computing which incorporates an additional kind of uncertainty, i.e. vagueness (fuzziness), in a natural way by introducing new entities, obscure qudits (e.g. obscure qubits), which are characterized simultaneously by a quantum probability and by a membership function. To achieve this, a membership amplitude for quantum states is introduced alongside the quantum amplitude. The Born rule is used for the quantum probability only, while the membership function can be computed from the membership amplitudes according to a chosen model. Two different versions of this approach are given here: the “product” obscure qubit, where the resulting amplitude is a product of the quantum amplitude and the membership amplitude, and the “Kronecker” obscure qubit, where quantum and vagueness computations are to be performed independently (i.e. quantum computation alongside truth evaluation). The latter is called a double obscure-quantum computation. In this case, the measurement becomes mixed in the quantum and obscure amplitudes, while the density matrix is not idempotent. The obscure-quantum gates act not in the tensor product of spaces, but in the direct product of quantum Hilbert space and so called membership space which are of different natures and properties. The concept of double (obscure-quantum) entanglement is introduced, and vector and scalar concurrences are proposed, with some examples being given.

Quantum optics with nitrogen-vacancy centres in diamond

2017 ◽  
Author(s):  
Yiwen Chu ◽  
Mikhail D. Lukin
Keyword(s):  
Optical Properties ◽  
Quantum Information ◽  
Solid State ◽  
Quantum Optics ◽  
Quantum States ◽  
Nitrogen Vacancy ◽  
Common Theme ◽  
External Effects ◽  
Promising Candidate ◽  
Optical Photons

A common theme in the implementation of quantum technologies involves addressing the seemingly contradictory needs for controllability and isolation from external effects. Undesirable effects of the environment must be minimized, while at the same time techniques and tools must be developed that enable interaction with the system in a controllable and well-defined manner. This chapter addresses several aspects of this theme with regard to a particularly promising candidate for developing applications in both metrology and quantum information, namely the nitrogen-vacancy (NV) centre in diamond. The chapter describes how the quantum states of NV centres can be manipulated, probed, and efficiently coupled with optical photons. It also discusses ways of tackling the challenges of controlling the optical properties of these emitters inside a complex solid state environment.

BOOK REVIEW: "PRINCIPLES OF QUANTUM COMPUTATION AND QUANTUM INFORMATION, Vol. I: BASIC CONCEPTS, VOL. II: BASIC TOOLS AND SPECIAL TOPICS" BY G. BENENTI, G. CASATI AND G. STRINI

2007 ◽  
Vol 05 (06) ◽  
pp. 913-921
Author(s):  
JÁNOS A. BERGOU
Keyword(s):  
Quantum Information ◽  
Quantum Computation ◽  
Current Literature ◽  
Reference Book ◽  
Introductory Course ◽  
Basic Concepts

This two-volume book is a great addition to the growing number of books devoted to the field. It is very clearly written by classroom professionals, always with the students in mind. The tutorial presentation is supplemented with a number of exercises whose solutions are also given at the end of each volume. The first volume can serve as a textbook for a one semester introductory course in quantum computation and quantum information. The second volume is more technical and brings the reader to the level of the current literature. It is useful for the specialist, can serve as a textbook for a more advanced course, or has its place as a reference book. In summary, I can highly recommend this book to anyone interested in this field.

EFFICIENT ALGORITHM FOR INITIALIZING AMPLITUDE DISTRIBUTION OF A QUANTUM REGISTER

2001 ◽  
Vol 15 (27) ◽  
pp. 1259-1264 ◽  
Author(s):  
M. ANDRECUT ◽  
M. K. ALI
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Quantum Computation ◽  
Quantum State ◽  
Efficient Algorithm ◽  
Quantum Information Processing ◽  
Amplitude Distribution ◽  
Quantum Register

The preparation of a quantum register in an arbitrary superposed quantum state is an important operation for quantum computation and quantum information processing. Here, we present an efficient algorithm which requires a polynomial number of elementary operations for initializing the amplitude distribution of a quantum register.

scholarly journals Quantum Switchboard with Coupled-Cavity Array

2021 ◽  
Author(s):  
Wai-Keong Mok ◽  
Leong-Chuan Kwek
Keyword(s):  
Quantum Information ◽  
Quantum Computation ◽  
Scaling Up ◽  
Quantum Network ◽  
Quantum Cloning ◽  
Physical Implementation ◽  
Large Quantum ◽  
Coupled Cavity ◽  
Cavity Array

The ability to control the flow of quantum information deterministically is useful for scaling up quantum computation. In this paper, we demonstrate a controllable quantum switchboard which directs the teleportation protocol to one of two targets, fully dependent on the sender’s choice. The quantum switchboard additionally acts as a optimal quantum cloning machine. We also provide a physical implementation of the proposal using a coupled-cavity array. The proposed switchboard can be utilized for the efficient routing of quantum information in a large quantum network.

Proposal for dimensionality testing in QPQ

2018 ◽  
Vol 18 (13&14) ◽  
pp. 1125-1142
Author(s):  
Arpita Maitra ◽  
Bibhas Adhikari ◽  
Satyabrata Adhikari
Keyword(s):  
Information Processing ◽  
Quantum Information ◽  
Quantum System ◽  
Quantum State ◽  
Quantum Information Processing ◽  
Quantum States ◽  
Quantum Private Query ◽  
Unfair Advantage ◽  
Security Proofs

Recently, dimensionality testing of a quantum state has received extensive attention (Ac{\'i}n et al. Phys. Rev. Letts. 2006, Scarani et al. Phys. Rev. Letts. 2006). Security proofs of existing quantum information processing protocols rely on the assumption about the dimension of quantum states in which logical bits are encoded. However, removing such assumption may cause security loophole. In the present paper, we show that this is indeed the case. We choose two players' quantum private query protocol by Yang et al. (Quant. Inf. Process. 2014) as an example and show how one player can gain an unfair advantage by changing the dimension of subsystem of a shared quantum system. To resist such attack we propose dimensionality testing in a different way. Our proposal is based on CHSH like game. As we exploit CHSH like game, it can be used to test if the states are product states for which the protocol becomes completely vulnerable.

Phase control for entanglement preparation in two-qubit systems

2005 ◽  
Vol 5 (4&5) ◽  
pp. 364-379
Author(s):  
V.S. Malinovsky ◽  
I.R. Sola
Keyword(s):  
Quantum Information ◽  
Quantum Computation ◽  
Quantum Control ◽  
Phase Control ◽  
Adiabatic Passage ◽  
Pulse Parameters ◽  
Qubit System ◽  
Phase Manipulation ◽  
Laser Control ◽  
Pi Pulses

The theory of Quantum Control is starting to lay bridges with the field of Quantum Information and Quantum Computation. Using key ideas of laser control of the dynamics by means of phase manipulation and adiabatic passage, we review laser schemes that allow entanglement preparation in a two-qubit system. The schemes are based on sequences that use four time-delayed pulses, with or without concerted decay, in or off resonance with the intermediate levels of the qubit space. We show how to control the fidelity and phase of the entanglement, as well as the sensitivity of the preparation to the different pulse parameters. In general the schemes provide an improvement in robustness and in the finesse of the control to phase, with respect to previously proposed schemes based on sequences of $\pi$ pulses.

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