Spin-based quantum computers made by chemistry: hows and whys†
... state of a Turing machine at any time can be understood in binary code as a string of 1s and 0s (or a sequence of on/off states, or up/down, or heads/tails, etc.). Even though real computers may not be constructed like a Turing machine (indeed Turing machines provide a very clumsy model for a realis ...
... state of a Turing machine at any time can be understood in binary code as a string of 1s and 0s (or a sequence of on/off states, or up/down, or heads/tails, etc.). Even though real computers may not be constructed like a Turing machine (indeed Turing machines provide a very clumsy model for a realis ...
Implementation of quantum logic gates using polar molecules in
... Quantum computers take direct advantage of superposition and entanglement to perform computations. Because quantum algorithms compute in ways which classical computers cannot, for certain problems they provide exponential speedups over their classical counterparts.1–8 That prospect has fostered a va ...
... Quantum computers take direct advantage of superposition and entanglement to perform computations. Because quantum algorithms compute in ways which classical computers cannot, for certain problems they provide exponential speedups over their classical counterparts.1–8 That prospect has fostered a va ...
Bohr`s quantum postulate and time in quantum mechanics
... ‘infinitesimal’ exchange of energy-momentum would enable us to define a quantum system independently of the experimental context where it is being observed. In his later writings the importance Bohr gave to this consequence of the quantum postulate became even clearer. In successive drafts for an ar ...
... ‘infinitesimal’ exchange of energy-momentum would enable us to define a quantum system independently of the experimental context where it is being observed. In his later writings the importance Bohr gave to this consequence of the quantum postulate became even clearer. In successive drafts for an ar ...
dagrep_v005_i004_p123_s15181. - DROPS
... and Rogaway, in which not only the algorithms, but also their security properties and the hardness properties upon which their security relies, are expressed as probabilistic programs , and can be verified using (a relational variant of) Hoare logic. This code-based approach is key to recent develop ...
... and Rogaway, in which not only the algorithms, but also their security properties and the hardness properties upon which their security relies, are expressed as probabilistic programs , and can be verified using (a relational variant of) Hoare logic. This code-based approach is key to recent develop ...
Experimental Realization of a Simple Entangling Optical Gate for
... qubits by applying CSIGN-gates between them. A CSIGN-gate introduces a controlled phase shift between individual qubits, such that |ii|ji → (−1)ij |ii|ji, with (i, j ∈ {0, 1}). This two-qubit gate together with single-qubit rotations, is universal for quantum computation, i.e. any arbitrary unitary ...
... qubits by applying CSIGN-gates between them. A CSIGN-gate introduces a controlled phase shift between individual qubits, such that |ii|ji → (−1)ij |ii|ji, with (i, j ∈ {0, 1}). This two-qubit gate together with single-qubit rotations, is universal for quantum computation, i.e. any arbitrary unitary ...
SEMICLASSICAL AND LARGE QUANTUM NUMBER LIMITS
... with d < −2 can support at most a finite number of bound states and the limit of (infinitely) large quantum numbers cannot be taken in the bound state regime. The semiclassical limit can be reached, however, e.g., by taking the limit of large potential strengths, see (3). When −2 < d < 0, large ener ...
... with d < −2 can support at most a finite number of bound states and the limit of (infinitely) large quantum numbers cannot be taken in the bound state regime. The semiclassical limit can be reached, however, e.g., by taking the limit of large potential strengths, see (3). When −2 < d < 0, large ener ...
A Quantum Query Expansion Approach for Session Search
... Piwowarski et al. [2] proposed that queries and documents can be modeled as density operators and subspaces respectively, but the tensor space based representation method has not led to a good retrieval performance. The Quantum Language Model (QLM) [4], a more recent QT-based IR model, successfully ...
... Piwowarski et al. [2] proposed that queries and documents can be modeled as density operators and subspaces respectively, but the tensor space based representation method has not led to a good retrieval performance. The Quantum Language Model (QLM) [4], a more recent QT-based IR model, successfully ...
Isolation of the Conceptual Ingredients of Quantum Theory by Toy
... ingredients can systematically be chosen to fully reproduce the mystery cake, and now by construction an accurate recipe is known. A toy theory is like a toy cake. It does not attempt to make statements about reality that might stand up to testing: any desirable qualities like this are purely coinci ...
... ingredients can systematically be chosen to fully reproduce the mystery cake, and now by construction an accurate recipe is known. A toy theory is like a toy cake. It does not attempt to make statements about reality that might stand up to testing: any desirable qualities like this are purely coinci ...
Shor`s Algorithm and Factoring: Don`t Throw Away the Odd Orders
... A problem arose when r = 2 and as/2 ≡ −1 mod N . In this case the A portion of the factorization was trivial: A = 1 and B = N . The same problem can happen for other prime divisors r of s. However if r does not divide N , the probability of this problem occurring goes to zero as r goes to infinity. ...
... A problem arose when r = 2 and as/2 ≡ −1 mod N . In this case the A portion of the factorization was trivial: A = 1 and B = N . The same problem can happen for other prime divisors r of s. However if r does not divide N , the probability of this problem occurring goes to zero as r goes to infinity. ...
Creation of entangled states in coupled quantum dots via adiabatic... C. Creatore, R. T. Brierley, R. T. Phillips,
... It is important to recognize that the requirement of exact degeneracy of the uncoupled transition is relaxed up to the magnitude of the coupling energy. This affords a route to practical realizations of the scheme, as the coupling energy and level splitting can be traded to optimize the probability ...
... It is important to recognize that the requirement of exact degeneracy of the uncoupled transition is relaxed up to the magnitude of the coupling energy. This affords a route to practical realizations of the scheme, as the coupling energy and level splitting can be traded to optimize the probability ...
Switching via quantum activation: A parametrically modulated oscillator 兲
... noise that leads to fluctuations 关4–12兴. Quantum nonequilibrium systems can also switch via tunneling between classically accessible regions of their phase space 关13–16兴. In addition to classical activation and quantum tunneling, nonequilibrium systems have another somewhat counterintuitive mechanis ...
... noise that leads to fluctuations 关4–12兴. Quantum nonequilibrium systems can also switch via tunneling between classically accessible regions of their phase space 关13–16兴. In addition to classical activation and quantum tunneling, nonequilibrium systems have another somewhat counterintuitive mechanis ...
Elementary gates for quantum computation
... Here we derive a series of results that provide tools for the building up of unitary transformations from simple gates. We build on other recent results that simplify and extend Deutsch's original discovery [24] of a three-bit universal quantum logic gate. As a consequence of the greater power of qu ...
... Here we derive a series of results that provide tools for the building up of unitary transformations from simple gates. We build on other recent results that simplify and extend Deutsch's original discovery [24] of a three-bit universal quantum logic gate. As a consequence of the greater power of qu ...
Quantum computing
Quantum computing studies theoretical computation systems (quantum computers) that make direct use of quantum-mechanical phenomena, such as superposition and entanglement, to perform operations on data. Quantum computers are different from digital computers based on transistors. Whereas digital computers require data to be encoded into binary digits (bits), each of which is always in one of two definite states (0 or 1), quantum computation uses quantum bits (qubits), which can be in superpositions of states. A quantum Turing machine is a theoretical model of such a computer, and is also known as the universal quantum computer. Quantum computers share theoretical similarities with non-deterministic and probabilistic computers. The field of quantum computing was initiated by the work of Yuri Manin in 1980, Richard Feynman in 1982, and David Deutsch in 1985. A quantum computer with spins as quantum bits was also formulated for use as a quantum space–time in 1968.As of 2015, the development of actual quantum computers is still in its infancy, but experiments have been carried out in which quantum computational operations were executed on a very small number of quantum bits. Both practical and theoretical research continues, and many national governments and military agencies are funding quantum computing research in an effort to develop quantum computers for civilian, business, trade, and national security purposes, such as cryptanalysis.Large-scale quantum computers will be able to solve certain problems much more quickly than any classical computers that use even the best currently known algorithms, like integer factorization using Shor's algorithm or the simulation of quantum many-body systems. There exist quantum algorithms, such as Simon's algorithm, that run faster than any possible probabilistic classical algorithm.Given sufficient computational resources, however, a classical computer could be made to simulate any quantum algorithm, as quantum computation does not violate the Church–Turing thesis.