General randomness amplification with non
... Let us first consider what it entails for statements like Theorem 1.2 to be true. We need to design a deterministic procedure that operates on some physical system with a single source of weak randomness with sufficient min-entropy (defined appropriately), and generates certifiable true randomness a ...
... Let us first consider what it entails for statements like Theorem 1.2 to be true. We need to design a deterministic procedure that operates on some physical system with a single source of weak randomness with sufficient min-entropy (defined appropriately), and generates certifiable true randomness a ...
Chapter 7 Practice Questions
... solutions of the Schrödinger equation for the electron in the hydrogen atom (i.e., which combination of quantum numbers is not allowed)? A) 9, 8, -4, 1/2 B) 8, 2, 2, 1/2 C) 6, -5, -1, 1/2 D) 6, 5, -5, 1/2 E) All are allowed. 26. Which of the following combinations of quantum numbers is not allowed? ...
... solutions of the Schrödinger equation for the electron in the hydrogen atom (i.e., which combination of quantum numbers is not allowed)? A) 9, 8, -4, 1/2 B) 8, 2, 2, 1/2 C) 6, -5, -1, 1/2 D) 6, 5, -5, 1/2 E) All are allowed. 26. Which of the following combinations of quantum numbers is not allowed? ...
Quantum Circuits Engineering: Efficient Simulation and
... menting specific algorithms, we have that knowledge because of the characteristic form these states exhibit. We have performed an analysis concerning the effectiveness of our methodology, for specific states from Shor and Grover algorithms. Unfortunately, as shown by our case study for Shor, Deutsch-Jo ...
... menting specific algorithms, we have that knowledge because of the characteristic form these states exhibit. We have performed an analysis concerning the effectiveness of our methodology, for specific states from Shor and Grover algorithms. Unfortunately, as shown by our case study for Shor, Deutsch-Jo ...
Limits on Efficient Computation in the Physical World
... More than a speculative technology, quantum computing seems to challenge our most basic intuitions about how the physical world should behave. In this thesis I show that, while some intuitions from classical computer science must be jettisoned in the light of modern physics, many others emerge nearl ...
... More than a speculative technology, quantum computing seems to challenge our most basic intuitions about how the physical world should behave. In this thesis I show that, while some intuitions from classical computer science must be jettisoned in the light of modern physics, many others emerge nearl ...
Multi-particle qubits - Department of Physics — ETH Zurich
... One can divide the non-linear computational mappings into three main categories: Projection on a two-level system (see Section 3.1.1), partial projection (see Section 3.1.2), and no projection at all (see Section 3.1.3). Projection on a two-level system is the most commonly used qubit encoding schem ...
... One can divide the non-linear computational mappings into three main categories: Projection on a two-level system (see Section 3.1.1), partial projection (see Section 3.1.2), and no projection at all (see Section 3.1.3). Projection on a two-level system is the most commonly used qubit encoding schem ...
Anyons and the quantum Hall effect— A pedagogical
... L being the circumference of the ring and m the electron mass. Quantum mechanically, if the electron was initially in the ground state it stays in an eigenstate, due to adiabaticity. It does not necessarily stay in the ground state, however. As the flux is being turned on, there are points of time in ...
... L being the circumference of the ring and m the electron mass. Quantum mechanically, if the electron was initially in the ground state it stays in an eigenstate, due to adiabaticity. It does not necessarily stay in the ground state, however. As the flux is being turned on, there are points of time in ...
1 Transport of Dirac Surface States
... the electrons lies in the anisotropy of scattering, even in the presence of ”isotropic impurities”. Naturally this property requires the use of a transport time, different from the elastic scattering time, to define the diffusion constant. For small samples in which transport can remain phase cohere ...
... the electrons lies in the anisotropy of scattering, even in the presence of ”isotropic impurities”. Naturally this property requires the use of a transport time, different from the elastic scattering time, to define the diffusion constant. For small samples in which transport can remain phase cohere ...
Time dependent entanglement features, and other quantum information aspects,
... In the non-Markovain regime, on the other hand (section 3.3), the environment correlation time is greater than, or of the same order as, the relaxation time over which the state of the system changes. “Memory effects” are thus considered important and are taken into account. The present study is ma ...
... In the non-Markovain regime, on the other hand (section 3.3), the environment correlation time is greater than, or of the same order as, the relaxation time over which the state of the system changes. “Memory effects” are thus considered important and are taken into account. The present study is ma ...
The inequality of charge and spin diffusion coefficients
... equal. In spin polarized transport, the two populations are unequal by definition. Therefore, it is imperative to examine if these two diffusion coefficients are still equal in spin polarized transport, and if not, then how unequal they can be. In this paper, we show that these two diffusion coeffic ...
... equal. In spin polarized transport, the two populations are unequal by definition. Therefore, it is imperative to examine if these two diffusion coefficients are still equal in spin polarized transport, and if not, then how unequal they can be. In this paper, we show that these two diffusion coeffic ...
Quantum key distribution
Quantum key distribution (QKD) uses quantum mechanics to guarantee secure communication. It enables two parties to produce a shared random secret key known only to them, which can then be used to encrypt and decrypt messages. It is often incorrectly called quantum cryptography, as it is the most well known example of the group of quantum cryptographic tasks.An important and unique property of quantum key distribution is the ability of the two communicating users to detect the presence of any third party trying to gain knowledge of the key. This results from a fundamental aspect of quantum mechanics: the process of measuring a quantum system in general disturbs the system. A third party trying to eavesdrop on the key must in some way measure it, thus introducing detectable anomalies. By using quantum superpositions or quantum entanglement and transmitting information in quantum states, a communication system can be implemented which detects eavesdropping. If the level of eavesdropping is below a certain threshold, a key can be produced that is guaranteed to be secure (i.e. the eavesdropper has no information about it), otherwise no secure key is possible and communication is aborted.The security of encryption that uses quantum key distribution relies on the foundations of quantum mechanics, in contrast to traditional public key cryptography which relies on the computational difficulty of certain mathematical functions, and cannot provide any indication of eavesdropping at any point in the communication process, or any mathematical proof as to the actual complexity of reversing the one-way functions used. QKD has provable security based on information theory, and forward secrecy.Quantum key distribution is only used to produce and distribute a key, not to transmit any message data. This key can then be used with any chosen encryption algorithm to encrypt (and decrypt) a message, which can then be transmitted over a standard communication channel. The algorithm most commonly associated with QKD is the one-time pad, as it is provably secure when used with a secret, random key. In real world situations, it is often also used with encryption using symmetric key algorithms like the Advanced Encryption Standard algorithm. In the case of QKD this comparison is based on the assumption of perfect single-photon sources and detectors, that cannot be easily implemented.