Search results for "Quantum computing"
showing 10 items of 49 documents
Simultaneous readout of two charge qubits
2006
We consider a system of two solid state charge qubits, coupled to a single read-out device, consisting of a single-electron transistor (SET). The conductance of each tunnel junction is influenced by its neighboring qubit, and thus the current through the transistor is determined by the qubits' state. The full counting statistics of the electrons passing the transistor is calculated, and we discuss qubit dephasing, as well as the quantum efficiency of the readout. The current measurement is then compared to readout using real-time detection of the SET island's charge state. For the latter method we show that the quantum efficiency is always unity. Comparing the two methods a simple geometric…
GENERATION OF ENTANGLED STATES OF TWO DISTANT CAVITY MODES VIA JOSEPHSON JUNCTION BASED DEVICES
2007
We present a simple scheme for the preparation of entangled states of the e.m. modes of two spatially separated microwave cavities exploiting their interaction with two superconducting SQUID rings embedded within them. The scheme requires that the two SQUID qubits are initially prepared in an entangled state and the possibility of controlling both the coupling strengths and the interaction times. We also briefly discuss the importance of such a theoretical scheme in view of possible applications in the context of quantum computing and its experimental feasibility.
Sing and Measure: Sound as Voice as Quanta
2022
The universal concept of a “music of the spheres” traverses the history of philosophy, science and art, from Pythagoras to Kepler and beyond. In modern times, a sphere in three dimensions—the Bloch sphere—is used to illustrate the state of a qubit, the basic unit of quantum information. On the same spherical surface, the fundamental components of voice production can be located, so that any utterance can be seen as the evolution of a unit two-dimensional vector having complex coefficients. Indeed, any sound can be analyzed and decomposed into overlapping sinusoidal components, broadband noises, and impulsive transients, which in turn can be associated to fundamental means of vocal sound pro…
Characterisation of the Degree of Musical Non-Markovianity
2022
As an aid for musical analysis, in computational musicology mathematical andinformatics tools have been developed to characterise quantitatively some aspectsof musical compositions. A musical composition can be attributed by ear a certainamount of memory. These results are associated with repetitions and similarities ofthe patterns in musical scores. To higher variations, a lower amount of memory isperceived. However, the musical memory of a score has never been quantitativelydefined. Here we aim to give such a measure following an approach similar tothat used in physics to quantify the memory (non-Markovianity) of open quantumsystems. We apply this measure to some existing musical composit…
Embracing iterations in Quantum software: a vision
2022
In today’s software engineering, iterations, affordable en masse, form an important part of just about any system. However, not all computing resources are cheap to consume. In High-Performance (HPC) and Quantum Computing (QC), executions can consume considerable amounts of energy and time, which is reserved and used even if the very first steps in the process fail. This means that developers must assume a different attitude towards programming, and aim at error-free software before its execution. This is com monly facilitated using simulators, which are commonplace for both HPC and QC. However the fashion developers advance from one tool to another is ad-hoc, with no established software e…
Quantum Creativity and Cognition in Humans and Robots
2022
In this research, we present a categorical framework to connect research on creativity and cognition for humans and robots, in light of the quantum paradigm. These fields and their relationships suggest a wider vision: modeling human creativity/cognition through quantum computing, and creating robots that can help us learn more about the humans themselves. We represent the human–robot comparison through functors (function generalization). Fundamental elements to understand human creativity are motivation and feedback as aesthetic pleasure. Is it possible to model it? Can the quantum paradigm help us in such an endeavor? We envisage the concept of emergence and quantum computing as decisive…
Modeling and designing a robotic swarm: A quantum computing approach
2023
Nature is a neverending source of inspiration for technology. Quantum physics suggests applications to- ward quantum computing. Swarms’ self-organization leads to robotic swarm developments. Here, quantum computing is applied to swarm robotics. We model local interactions with a quantum circuit, testing it on simulators and quantum computers. To relate local with global behavior, we develop a block matrix-based model. Diagonal sub-matrices contain information on single robots; off-diagonal sub-matrices are the pairwise interaction terms. Comparing different swarms means comparing different block matrices. Choosing initial values and computation rules for off-diagonal blocks (with a particul…
Enhancing coherence in molecular spin qubits via atomic clock transitions
2016
Quantum computing is an emerging area within the information sciences revolving around the concept of quantum bits (qubits). A major obstacle is the extreme fragility of these qubits due to interactions with their environment that destroy their quantumness. This phenomenon, known as decoherence, is of fundamental interest1,2. There are many competing candidates for qubits, including superconducting circuits3, quantum optical cavities4, ultracold atoms5 and spin qubits6,7,8, and each has its strengths and weaknesses. When dealing with spin qubits, the strongest source of decoherence is the magnetic dipolar interaction9. To minimize it, spins are typically diluted in a diamagnetic matrix. For…
Supervised learning of time-independent Hamiltonians for gate design
2018
We present a general framework to tackle the problem of finding time-independent dynamics generating target unitary evolutions. We show that this problem is equivalently stated as a set of conditions over the spectrum of the time-independent gate generator, thus transforming the task to an inverse eigenvalue problem. We illustrate our methodology by identifying suitable time-independent generators implementing Toffoli and Fredkin gates without the need for ancillae or effective evolutions. We show how the same conditions can be used to solve the problem numerically, via supervised learning techniques. In turn, this allows us to solve problems that are not amenable, in general, to direct ana…
A Quantum Planner for Robot Motion
2022
The possibility of integrating quantum computation in a traditional system appears to be a viable route to drastically improve the performance of systems endowed with artificial intelligence. An example of such processing consists of implementing a teleo-reactive system employing quantum computing. In this work, we considered the navigation of a robot in an environment where its decisions are drawn from a quantum algorithm. In particular, the behavior of a robot is formalized through a production system. It is used to describe the world, the actions it can perform, and the conditions of the robot’s behavior. According to the production rules, the planning of the robot activities is processe…