How Many Query Superpositions Are Needed to Learn?
... (or query complexity) required by exact learners. Our aim is to obtain lower and upper bounds on the query complexity that are valid under any choice of queries defining the learning game. According to the first goal, we introduce in Sect. 3 the quantum protocol concept, a notion that allows us to d ...
... (or query complexity) required by exact learners. Our aim is to obtain lower and upper bounds on the query complexity that are valid under any choice of queries defining the learning game. According to the first goal, we introduce in Sect. 3 the quantum protocol concept, a notion that allows us to d ...
Composing Quantum Protocols in a Classical Environment
... remains classical. From a more theoretical point of view, our general security definition expresses what security properties a quantum protocol must satisfy in order to be able to instantiate a basic cryptographic primitive upon which an information-theoretic cryptographic construction is based. For ...
... remains classical. From a more theoretical point of view, our general security definition expresses what security properties a quantum protocol must satisfy in order to be able to instantiate a basic cryptographic primitive upon which an information-theoretic cryptographic construction is based. For ...
Feynman-Kac formula for L´evy processes and semiclassical (Euclidean) momentum representation
... (Euclidean) quantum mechanics in several special cases, and we derive precise asymptotics as well for the drift terms in both configuration and momentum representations. The reader is referred to [28] for more about the underlying notion of Euclidean quantum mechanics. This paper is organized as fol ...
... (Euclidean) quantum mechanics in several special cases, and we derive precise asymptotics as well for the drift terms in both configuration and momentum representations. The reader is referred to [28] for more about the underlying notion of Euclidean quantum mechanics. This paper is organized as fol ...
Quantum Symmetric States - UCLA Department of Mathematics
... To investigate QSS(A) as a compact, convex subset of S(A), to characterize its extreme points and to study certain convex subsets: • the tracial quantum symmetric states TQSS(A) = QSS(A) ∩ T S(A) • the central quantum symmetric states ZQSS(A) = {ψ ∈ QSS(A) | Tψ ⊆ Z(Mψ )} • the tracial central quantu ...
... To investigate QSS(A) as a compact, convex subset of S(A), to characterize its extreme points and to study certain convex subsets: • the tracial quantum symmetric states TQSS(A) = QSS(A) ∩ T S(A) • the central quantum symmetric states ZQSS(A) = {ψ ∈ QSS(A) | Tψ ⊆ Z(Mψ )} • the tracial central quantu ...
Quantum networking with single ions J¨ urgen Eschner
... Possible causes of decoherence in this process of generating a pure single-photon quantum state include both technical deficiencies and fundamental issues. On the technical side, any jitter in the emission time or frequency, resulting for example from fluctuations in the laser frequency or intensity ...
... Possible causes of decoherence in this process of generating a pure single-photon quantum state include both technical deficiencies and fundamental issues. On the technical side, any jitter in the emission time or frequency, resulting for example from fluctuations in the laser frequency or intensity ...
slides on Quantum Isometry Groups
... In the above formulation, the choice of R-twisted volume form τR may seem ad-hoc and it is indeed desirable to understand when an orientation-preserving quantum isometric action automatically preserves some canonical τR . In such a case there is no need to artificially choose and fix any τR . We sta ...
... In the above formulation, the choice of R-twisted volume form τR may seem ad-hoc and it is indeed desirable to understand when an orientation-preserving quantum isometric action automatically preserves some canonical τR . In such a case there is no need to artificially choose and fix any τR . We sta ...
Quantum Thermodynamics: A Dynamical Viewpoint
... Empirically, it is known that faster motion leads to losses, due to friction. The quantum description identifies the source of friction in the inability of the system to stay diagonal in the instantaneous energy frame [27,36–39]. Once energy is accounted for, which in an engine cycle, occurs on the ...
... Empirically, it is known that faster motion leads to losses, due to friction. The quantum description identifies the source of friction in the inability of the system to stay diagonal in the instantaneous energy frame [27,36–39]. Once energy is accounted for, which in an engine cycle, occurs on the ...
Optimal Inequalities for State-Independent Contextuality Linköping University Post Print
... operators on a two-qubit system, ( ) [22]. The optimal violation is V ¼ 2=3, where only contexts of size three need to be measured and c ¼ 1=15, except xx;yy;zz ¼ xz;yx;zy ¼ xy;yz;zx ¼ 1=15. Among the optimal solutions no simpler inequality exists. (ii) The 18 vector proof [23] of the Ko ...
... operators on a two-qubit system, ( ) [22]. The optimal violation is V ¼ 2=3, where only contexts of size three need to be measured and c ¼ 1=15, except xx;yy;zz ¼ xz;yx;zy ¼ xy;yz;zx ¼ 1=15. Among the optimal solutions no simpler inequality exists. (ii) The 18 vector proof [23] of the Ko ...
The Light of Existence
... The grid as a network with a base cycle rate also keeps photons in strict sequence, one behind the other, like the baggage cars of a train driven by the same engine. Each node passes on the photon it has then accepts another in the line. If the engine slows down under load, say near a massive star, ...
... The grid as a network with a base cycle rate also keeps photons in strict sequence, one behind the other, like the baggage cars of a train driven by the same engine. Each node passes on the photon it has then accepts another in the line. If the engine slows down under load, say near a massive star, ...
Particle in a box
In quantum mechanics, the particle in a box model (also known as the infinite potential well or the infinite square well) describes a particle free to move in a small space surrounded by impenetrable barriers. The model is mainly used as a hypothetical example to illustrate the differences between classical and quantum systems. In classical systems, for example a ball trapped inside a large box, the particle can move at any speed within the box and it is no more likely to be found at one position than another. However, when the well becomes very narrow (on the scale of a few nanometers), quantum effects become important. The particle may only occupy certain positive energy levels. Likewise, it can never have zero energy, meaning that the particle can never ""sit still"". Additionally, it is more likely to be found at certain positions than at others, depending on its energy level. The particle may never be detected at certain positions, known as spatial nodes.The particle in a box model provides one of the very few problems in quantum mechanics which can be solved analytically, without approximations. This means that the observable properties of the particle (such as its energy and position) are related to the mass of the particle and the width of the well by simple mathematical expressions. Due to its simplicity, the model allows insight into quantum effects without the need for complicated mathematics. It is one of the first quantum mechanics problems taught in undergraduate physics courses, and it is commonly used as an approximation for more complicated quantum systems.