scholarly journals Increasing the Hilbert space dimension using a single coupled molecular spin

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Hugo Biard ◽  
Eufemio Moreno-Pineda ◽  
Mario Ruben ◽  
Edgar Bonet ◽  
Wolfgang Wernsdorfer ◽  
...  
Keyword(s):  
Hilbert Space ◽  
Integrated Circuits ◽  
Quantum Algorithms ◽  
Quantum Systems ◽  
Molecular Magnets ◽  
Molecular Magnet ◽  
Quantum Objects ◽  
Multi Level ◽  
Quantum Technology ◽  
Near Future

AbstractQuantum technologies are expected to introduce revolutionary changes in information processing in the near future. Nowadays, one of the main challenges is to be able to handle a large number of quantum bits (qubits), while preserving their quantum properties. Beyond the usual two-level encoding capacity of qubits, multi-level quantum systems are a promising way to extend and increase the amount of information that can be stored in the same number of quantum objects. Recent work (Kues et al. 2017), has shown the possibility to use devices based on photonic integrated circuits to entangle two qudits (with “d” being the number of available states). In the race to develop a mature quantum technology with real-world applications, many possible platforms are being investigated, including those that use photons, trapped ions, superconducting and silicon circuits and molecular magnets. In this work, we present the electronic read-out of a coupled molecular multi-level quantum systems, carried by a single Tb2Pc3 molecular magnet. Owning two magnetic centres, this molecular magnet architecture permits a 16 dimensions Hilbert space, opening the possibility of performing more complex quantum algorithms.

The Essence of Quantum Computing

2018 ◽  
Author(s):  
Rajendra K. Bera
Keyword(s):  
Hilbert Space ◽  
Quantum Computing ◽  
Quantum Physics ◽  
Quantum Algorithms ◽  
Quantum Computers ◽  
Turing Machines ◽  
Classical Physics ◽  
Core Set ◽  
The World ◽  
Subordinate Role

It now appears that quantum computers are poised to enter the world of computing and establish its dominance, especially, in the cloud. Turing machines (classical computers) tied to the laws of classical physics will not vanish from our lives but begin to play a subordinate role to quantum computers tied to the enigmatic laws of quantum physics that deal with such non-intuitive phenomena as superposition, entanglement, collapse of the wave function, and teleportation, all occurring in Hilbert space. The aim of this 3-part paper is to introduce the readers to a core set of quantum algorithms based on the postulates of quantum mechanics, and reveal the amazing power of quantum computing.

Thermal-aware Output Polarity Selection Based on And-Inverter Graph Manipulation

2019 ◽  
Vol 12 (1) ◽  
pp. 30-39 ◽  
Author(s):  
Apangshu Das ◽  
Sambhu Nath Pradhan
Keyword(s):  
Integrated Circuits ◽  
Power Density ◽  
Logic Synthesis ◽  
Programmable Logic Arrays ◽  
Power Switching ◽  
Nsga Ii ◽  
Multi Level ◽  
Search Approach ◽  
Efficient Power ◽  
The Impact

Background: Output polarity of the sub-function is generally considered to reduce the area and power of a circuit at the two-level realization. Along with area and power, the power-density is also one of the significant parameter which needs to be consider, because power-density directly converges to circuit temperature. More than 50% of the modern day integrated circuits are damaged due to excessive overheating. Methods: This work demonstrates the impact of efficient power density based logic synthesis (in the form of suitable polarity selection of sub-function of Programmable Logic Arrays (PLAs) for its multilevel realization) for the reduction of temperature. Two-level PLA optimization using output polarity selection is considered first and compared with other existing techniques and then And-Invert Graphs (AIG) based multi-level realization has been considered to overcome the redundant solution generated in two-level synthesis. AIG nodes and associated power dissipation can be reduced by rewriting, refactoring and balancing technique. Reduction of nodes leads to the reduction of the area but on the contrary increases power and power density of the circuit. A meta-heuristic search approach i.e., Nondominated Sorting Genetic Algorithm-II (NSGA-II) is proposed to select the suitable output polarity of PLA sub-functions for its optimal realization. Results: Best power density based solution saves up to 8.29% power density compared to ‘espresso – dopo’ based solutions. Around 9.57% saving in area and 9.67% saving in power (switching activity) are obtained with respect to ‘espresso’ based solution using NSGA-II. Conclusion: Suitable output polarity realized circuit is converted into multi-level AIG structure and synthesized to overcome the redundant solution at the two-level circuit. It is observed that with the increase in power density, the temperature of a particular circuit is also increases.

scholarly journals A variational toolbox for quantum multi-parameter estimation

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Johannes Jakob Meyer ◽  
Johannes Borregaard ◽  
Jens Eisert
Keyword(s):  
Parameter Estimation ◽  
Information Science ◽  
Quantum Algorithms ◽  
Continuous Variable ◽  
General Interest ◽  
Quantum Metrology ◽  
Estimation Problems ◽  
General Parameter ◽  
Quantum Technology ◽  
Aided Design

AbstractWith an ever-expanding ecosystem of noisy and intermediate-scale quantum devices, exploring their possible applications is a rapidly growing field of quantum information science. In this work, we demonstrate that variational quantum algorithms feasible on such devices address a challenge central to the field of quantum metrology: The identification of near-optimal probes and measurement operators for noisy multi-parameter estimation problems. We first introduce a general framework that allows for sequential updates of variational parameters to improve probe states and measurements and is widely applicable to both discrete and continuous-variable settings. We then demonstrate the practical functioning of the approach through numerical simulations, showcasing how tailored probes and measurements improve over standard methods in the noisy regime. Along the way, we prove the validity of a general parameter-shift rule for noisy evolutions, expected to be of general interest in variational quantum algorithms. In our approach, we advocate the mindset of quantum-aided design, exploiting quantum technology to learn close to optimal, experimentally feasible quantum metrology protocols.

scholarly journals Timelessness Strictly Inside the Quantum Realm

Entropy ◽  
2021 ◽  
Vol 23 (6) ◽  
pp. 772
Author(s):  
Knud Thomsen
Keyword(s):  
Real World ◽  
Quantum Physics ◽  
Quantum Systems ◽  
The Real ◽  
Classical World ◽  
Quantum Objects ◽  
The Everyday ◽  
Double Slit

Time is one of the undisputed foundations of our life in the real world. Here it is argued that inside small isolated quantum systems, time does not pass as we are used to, and it is primarily in this sense that quantum objects enjoy only limited reality. Quantum systems, which we know, are embedded in the everyday classical world. Their preparation as well as their measurement-phases leave durable records and traces in the entropy of the environment. The Landauer Principle then gives a quantitative threshold for irreversibility. With double slit experiments and tunneling as paradigmatic examples, it is proposed that a label of timelessness offers clues for rendering a Copenhagen-type interpretation of quantum physics more “realistic” and acceptable by providing a coarse but viable link from the fundamental quantum realm to the classical world which humans directly experience.

scholarly journals Selective Phase Rotation Quantum Gate Entangler

2009 ◽  
Vol 16 (04) ◽  
pp. 407-412
Author(s):  
Hoshang Heydari
Keyword(s):  
Integral Transform ◽  
Quantum Algorithms ◽  
Quantum Systems ◽  
Quantum Gate ◽  
Multipartite Quantum Systems ◽  
Phase Rotation ◽  
Quantum Integral ◽  
Qubit States

We construct a quantum gate entangler for multi-qubit states based on a selective phase rotation transform. In particular, we establish a relation between the quantum integral transform and the quantum gate entangler in terms of universal controlled gates for multi-qubit states. Our result gives an effective way of constructing topological and geometrical quantum gate entanglers for multipartite quantum systems, which could also lead to a construction of geometrical quantum algorithms.

scholarly journals Paths of unitary access to exceptional points

2021 ◽  
Vol 2038 (1) ◽  
pp. 012026
Author(s):  
Miloslav Znojil
Keyword(s):  
Hilbert Space ◽  
Phase Transitions ◽  
Quantum Phase Transitions ◽  
Quantum Systems ◽  
Point Of View ◽  
Explicit Description ◽  
Direct Access ◽  
Exceptional Point ◽  
Exceptional Points ◽  
Innovative Idea

Abstract With an innovative idea of acceptability and usefulness of the non-Hermitian representations of Hamiltonians for the description of unitary quantum systems (dating back to the Dyson’s papers), the community of quantum physicists was offered a new and powerful tool for the building of models of quantum phase transitions. In this paper the mechanism of such transitions is discussed from the point of view of mathematics. The emergence of the direct access to the instant of transition (i.e., to the Kato’s exceptional point) is attributed to the underlying split of several roles played by the traditional single Hilbert space of states ℒ into a triplet (viz., in our notation, spaces K and ℋ besides the conventional ℒ ). Although this explains the abrupt, quantum-catastrophic nature of the change of phase (i.e., the loss of observability) caused by an infinitesimal change of parameters, the explicit description of the unitarity-preserving corridors of access to the phenomenologically relevant exceptional points remained unclear. In the paper some of the recent results in this direction are summarized and critically reviewed.

scholarly journals Advancing Frontier Nanophysics in Time of Analytical Chemistry: Who to educate first?

2020 ◽  
Vol 3 (3) ◽  
pp. 275-281
Author(s):  
Hendry Izaac Elim
Keyword(s):  
Analytical Chemistry ◽  
Integrated Circuits ◽  
Molecular System ◽  
Herbal Medicines ◽  
Industrial Applications ◽  
Pharmaceutical Drugs ◽  
Applied Physics ◽  
The Origin Of Life ◽  
Level Of Understanding ◽  
Near Future

Frontier nanophysics in conjunction with nanomedicines, nanoscience and nanotechnology (NNN) developed before the science of analytical chemistry has been very challenges with many competitive obstacles to improve the accuracy and precise nm measurements in order to find out the point of its main chemical structure compositions, uniformity and the concentration contents to each substance. Moreover, exotics nanomaterials either in pure organic and inorganic compound or in hybrid organic-inorganics nanomaterials have shown their remarkable as well as attractive impacts in many nanotechnology and related industrial applications such as in ultrafast picosecond or femtosecond telecommunication integrated circuits and devices system, cosmetics and beauty products, as well as health or pharmaceutical drugs and herbal medicines. In this short communication paper, one explains how to educate first those who are eager indeed to study and expand their knowledge in the discovery level of understanding the nature of chemistry materials. Such guide will involve at least two to three parts of knowledge and skills consisted of the origin of life, electronics of molecular system (MES), and precise or accurate measurements. By implementing these advices, one believes the progress of applied physics frontier works in analytical chemistry will soon obtain a good harvest in the near future.

scholarly journals Using quantum computing to create efficient algorithms

2021 ◽  
Vol 2056 (1) ◽  
pp. 012059
Author(s):  
I N Balaba ◽  
G S Deryabina ◽  
I A Pinchuk ◽  
I V Sergeev ◽  
S B Zabelina
Keyword(s):  
Quantum Mechanics ◽  
Quantum Computing ◽  
Computational Model ◽  
Exponential Growth ◽  
Quantum Algorithms ◽  
Quantum Systems ◽  
Efficient Algorithms ◽  
Historical Overview ◽  
Computing Model ◽  
Computational Strategy

Abstract The article presents a historical overview of the development of the mathematical idea of a quantum computing model - a new computational strategy based on the postulates of quantum mechanics and having advantages over the traditional computational model based on the Turing machine; clarified the features of the operation of multi-qubit quantum systems, which ensure the creation of efficient algorithms; the principles of quantum computing are outlined and a number of efficient quantum algorithms are described that allow solving the problem of exponential growth of the complexity of certain problems.

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