Structure and Computational Basis for Backbone Rearrangement in Marine Oxasqualenoids

2020 ◽  
Author(s):  
Francisco Cen-Pacheco ◽  
Adrián J. Santiago-Benítez ◽  
Ka Yi Tsui ◽  
Dean J. Tantillo ◽  
José J. Fernández ◽  
...  
Keyword(s):  
Computational Basis

QUANTUM COMPUTATIONAL SCHEMES GENERATED BY k-BOSON ALGEBRAS

2007 ◽  
Vol 05 (01n02) ◽  
pp. 229-234
Author(s):  
FRANCESCO A. RAFFA ◽  
MARIO RASETTI
Keyword(s):  
Cnot Gate ◽  
Logical Operators ◽  
Computational Schemes ◽  
Computational Basis

It is shown that a multiboson (k-boson) algebra can be conveniently utilized to generate a k-dimensional computational basis. The single qukit logical operators are given ∀k and two different constructions of the CNOT gate are presented.

Computational basis of decision-making impairment in multiple sclerosis

2021 ◽  
pp. 135245852110593
Author(s):  
Rodrigo S Fernández ◽  
Lucia Crivelli ◽  
María E Pedreira ◽  
Ricardo F Allegri ◽  
Jorge Correale
Keyword(s):  
Multiple Sclerosis ◽  
Decision Making ◽  
Computational Models ◽  
Iowa Gambling Task ◽  
Memory Impairments ◽  
Hierarchical Bayesian Analysis ◽  
Control Subjects ◽  
Neurocognitive Impairments ◽  
Neurocognitive Evaluation ◽  
Computational Basis

Background: Multiple sclerosis (MS) is commonly associated with decision-making, neurocognitive impairments, and mood and motivational symptoms. However, their relationship may be obscured by traditional scoring methods. Objectives: To study the computational basis underlying decision-making impairments in MS and their interaction with neurocognitive and neuropsychiatric measures. Methods: Twenty-nine MS patients and 26 matched control subjects completed a computer version of the Iowa Gambling Task (IGT). Participants underwent neurocognitive evaluation using an expanded version of the Brief Repeatable Battery. Hierarchical Bayesian Analysis was used to estimate three established computational models to compare parameters between groups. Results: Patients showed increased learning rate and reduced loss-aversion during decision-making relative to control subjects. These alterations were associated with: (1) reduced net gains in the IGT; (2) processing speed, executive functioning and memory impairments; and (3) higher levels of depression and current apathy. Conclusion: Decision-making deficits in MS patients could be described by the interplay between latent computational processes, neurocognitive impairments, and mood/motivational symptoms.

scholarly journals Measuring the Tangle of Three-Qubit States

Entropy ◽  
2020 ◽  
Vol 22 (4) ◽  
pp. 436 ◽  
Author(s):  
Adrián Pérez-Salinas ◽  
Diego García-Martín ◽  
Carlos Bravo-Prieto ◽  
José Latorre
Keyword(s):  
Direct Measurement ◽  
Canonical Form ◽  
Quantum Circuit ◽  
Quantum Gates ◽  
Tripartite Entanglement ◽  
Single Qubit ◽  
Optimal Values ◽  
Random States ◽  
Qubit States ◽  
Computational Basis

We present a quantum circuit that transforms an unknown three-qubit state into its canonical form, up to relative phases, given many copies of the original state. The circuit is made of three single-qubit parametrized quantum gates, and the optimal values for the parameters are learned in a variational fashion. Once this transformation is achieved, direct measurement of outcome probabilities in the computational basis provides an estimate of the tangle, which quantifies genuine tripartite entanglement. We perform simulations on a set of random states under different noise conditions to asses the validity of the method.

Multiparty semiquantum secret sharing based on rearranging orders of qubits

2016 ◽  
Vol 30 (10) ◽  
pp. 1650130 ◽  
Author(s):  
Gan Gao ◽  
Yue Wang ◽  
Dong Wang
Keyword(s):  
Secret Sharing ◽  
Key Distribution ◽  
Bell States ◽  
Secret Key ◽  
Computational Basis

Based on the assumption of a perfect qubit, Boyer et al. proposed a novel semiquantum key distribution protocol [Phys. Rev. Lett. 99 (2007) 140501], in which quantum Alice shares a secret key with classical Bob. In this paper, we use Bell states to propose a multiparty semiquantum secret sharing (MSQSS) protocol, in which only the boss is quantum and all agents are classical. Classical agents are restricted to performing measurements in a computational basis and rearranging orders of qubits. Unless all classical agents collaborate, no subset of them can obtain the secret of the quantum boss. Also, we show that this proposed protocol is secure against eavesdropping.

scholarly journals DIAGONAL-UNITARY 2-DESIGN AND THEIR IMPLEMENTATIONS BY QUANTUM CIRCUITS

2013 ◽  
Vol 11 (07) ◽  
pp. 1350062 ◽  
Author(s):  
YOSHIFUMI NAKATA ◽  
MIO MURAO
Keyword(s):  
Algebraic Structure ◽  
Quantum Circuits ◽  
Random Choice ◽  
Unitary Matrices ◽  
Single Qubit ◽  
Classical Procedure ◽  
Random States ◽  
Computational Basis

We study efficient generations of random diagonal-unitary matrices, an ensemble of unitary matrices diagonal in a given basis with randomly distributed phases for their eigenvalues. Despite the simple algebraic structure, they cannot be achieved by quantum circuits composed of a few-qubit diagonal gates. We introduce diagonal-unitaryt-designs and present two quantum circuits that implement diagonal-unitary 2-design with the computational basis in N-qubit systems. One is composed of single-qubit diagonal gates and controlled-phase gates with randomized phases, which achieves an exact diagonal-unitary 2-design after applying the gates on all pairs of qubits. The number of required gates is N(N - 1)/2. If the controlled-Z gates are used instead of the controlled-phase gates, the circuit cannot achieve an exact 2-design, but achieves an ϵ-approximate 2-design by applying gates on randomly selected pairs of qubits. Due to the random choice of pairs, the circuit obtains extra randomness and the required number of gates is at most O(N2(N + log 1/∊)). We also provide an application of the circuits, a protocol of generating an exact 2-design of random states by combining the circuits with a simple classical procedure requiring O(N) random classical bits.

Damage to Object Oriented Programming in the Brain Explains many of the Psychopathological Features of Schizophrenia

2009 ◽  
Vol 24 (S1) ◽  
pp. 1-1
Author(s):  
C.P. Arun
Keyword(s):  
Object Representation ◽  
Object Oriented ◽  
Computational Effort ◽  
Object Oriented Programming ◽  
Programming Technique ◽  
The Brain ◽  
Computational Basis ◽  
Psychopathology Of Schizophrenia ◽  
Hand Action ◽  
Oriented Programming Language

Introduction:Modern computers often use programs that incorporate a programming technique called Object Oriented Programming (OOP), allowing users to manipulate complex ‘computational objects’ such as menus, screen windows, etc with very little effort, say the click of a mouse. OOP deals with structures called objects and allows time and computational effort saving devices such as inheritance, polymorphism and encapsulation. We examine whether the brain itself may use OOP and if representation of objects suffers a breakdown in schizophrenia.Review of literature:Previous models fail to provide a unifying explanation with a computational basis that could explain the psychopathology in schizophrenia. METHODS Using the object oriented programming language JavaTM we designed a system of self-objects named ‘hand’, ‘action monitor’ etc interacting with non-self objects ‘scissors’, ‘hammer’, ‘wall’, etc. in computational experiments, we allow the ‘action monitor’ to fail; the features of disparate objects are allowed to merge, some features of an object are allowed to be shared with other objects, etc.Results:By transposing only a few lines of code, it is possible to duplicate various features of the psychopathology of schizophrenia.Discussion:Our model can demonstrate overinclusion (overabstraction), concrete thinking (underabstraction), loss of ego boundaries (conjoining of disparate objects), delusions (misattribution of object function), lack of insight (poor monitoring of object activity) and passivity (loss of monitoring and misattribution of object activity).Conclusion:The brain must use the OOP model in its computations. Failure of object representation and manipulation must lie at the core of the psychopathology of schizophrenia.

scholarly journals Heuristic for estimation of multiqubit genuine multipartite entanglement

2015 ◽  
Vol 13 (03) ◽  
pp. 1550023 ◽  
Author(s):  
Paulo E. M. F. Mendonça ◽  
Marcelo A. Marchiolli ◽  
Gerard J. Milburn
Keyword(s):  
Lower Bound ◽  
Density Matrix ◽  
Lower Bounds ◽  
Multipartite Entanglement ◽  
Zero Temperature ◽  
Mixed States ◽  
X State ◽  
Computational Basis ◽  
Genuine Multipartite Entanglement

For every N-qubit density matrix written in the computational basis, an associated "X-density matrix" can be obtained by vanishing all entries out of the main- and anti-diagonals. It is very simple to compute the genuine multipartite (GM) concurrence of this associated N-qubit X-state, which, moreover, lower bounds the GM-concurrence of the original (non-X) state. In this paper, we rely on these facts to introduce and benchmark a heuristic for estimating the GM-concurrence of an arbitrary multiqubit mixed state. By explicitly considering two classes of mixed states, we illustrate that our estimates are usually very close to the standard lower bound on the GM-concurrence, being significantly easier to compute. In addition, while evaluating the performance of our proposed heuristic, we provide the first characterization of GM-entanglement in the steady states of the driven Dicke model at zero temperature.

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