Recent Progress in Ultracold Atoms
... •Ring trap •Chips New Probes •RF Spectroscopy •Noise Correlations •Birefringence ...
... •Ring trap •Chips New Probes •RF Spectroscopy •Noise Correlations •Birefringence ...
GRW Theory - Roman Frigg
... pk (c) = 5Lk,c |S 5 ; the width σ of the Gaussian is also a new constant of nature, and it is of the magnitude 10−7 m. The choice of this distribution assures that the predictions of GRW Theory coincide almost always with those of standard QM (there are domains in which the two theories do not yie ...
... pk (c) = 5Lk,c |S 5 ; the width σ of the Gaussian is also a new constant of nature, and it is of the magnitude 10−7 m. The choice of this distribution assures that the predictions of GRW Theory coincide almost always with those of standard QM (there are domains in which the two theories do not yie ...
Reivelt, K., Vlassov, S. (2014) Quantum SpinOff Learning Station
... and hydrogen atoms. We have also learned about some quantum-mechanical phenomena like light emission and tunneling. However, realistic quantum mechanical systems consist of many atoms or molecules, and we are not able to investigate those systems by exact mathematical formulae. In general, even when ...
... and hydrogen atoms. We have also learned about some quantum-mechanical phenomena like light emission and tunneling. However, realistic quantum mechanical systems consist of many atoms or molecules, and we are not able to investigate those systems by exact mathematical formulae. In general, even when ...
Quantum Wires and Quantum Point Contacts
... leads are described by the Fermi functions, i. e., the leads are in the equilibrium. Such an equilibrium is achieved only at the distances larger than the electron mean free path. Thus, the dissipation takes place in the leads close to the contacts. What we have calculated is the total resistance of ...
... leads are described by the Fermi functions, i. e., the leads are in the equilibrium. Such an equilibrium is achieved only at the distances larger than the electron mean free path. Thus, the dissipation takes place in the leads close to the contacts. What we have calculated is the total resistance of ...
a simple explanation of search technique in quantum framework
... This parallelism provides the distinction between classical and quantum algorithmic strategies. For an example the objective of a classical algorithm is to reduce the amplitude of non target states, where as a quantum search algorithm tries to amplify the amplitude of the target states. Here the ter ...
... This parallelism provides the distinction between classical and quantum algorithmic strategies. For an example the objective of a classical algorithm is to reduce the amplitude of non target states, where as a quantum search algorithm tries to amplify the amplitude of the target states. Here the ter ...
Population Inversion in a Single InGaAs Quantum Dot Using
... pulses is generated by a parallel grating pair with 1200 grooves=mm. The value of the chirp can be changed by varying the distance between the gratings. The laser light is focused by the objective down to 1 m over a 200 nm aperture in a gold mask. The sample consists of a single layer of InGaAs qu ...
... pulses is generated by a parallel grating pair with 1200 grooves=mm. The value of the chirp can be changed by varying the distance between the gratings. The laser light is focused by the objective down to 1 m over a 200 nm aperture in a gold mask. The sample consists of a single layer of InGaAs qu ...
Chaos and the semiclassical limit of quantum mechanics (is the
... tendrils exploring the whole phase sphere. The area enclosed by B(t) remains constant (this is Liouville’s theorem); however B’s perimeter length grows exponentially, as L(t)≈L(0)exp(t/Tc), where for Hyperion the chaos time is Tc≈100 days. Classically, the convolutions get ever more intricate. For a ...
... tendrils exploring the whole phase sphere. The area enclosed by B(t) remains constant (this is Liouville’s theorem); however B’s perimeter length grows exponentially, as L(t)≈L(0)exp(t/Tc), where for Hyperion the chaos time is Tc≈100 days. Classically, the convolutions get ever more intricate. For a ...
PPT
... develop correlations with some particular states of an outside system – associated with quantum gravity? • So far this is not news. But now let the process by which those correlations develop be non-linear, e.g. it happens only when the measure of the state along some pointer reaches a threshold val ...
... develop correlations with some particular states of an outside system – associated with quantum gravity? • So far this is not news. But now let the process by which those correlations develop be non-linear, e.g. it happens only when the measure of the state along some pointer reaches a threshold val ...
A Full-Quantum Three-Dimensional Analysis of the Dynamics of a
... right sequence and at just the right strengths. Thus, the fact is that mostly the atoms are trapped in a single potential minimum until they leave the interaction region. Nevertheless, it is interesting to see how the classical picture mimics the quantum description. ...
... right sequence and at just the right strengths. Thus, the fact is that mostly the atoms are trapped in a single potential minimum until they leave the interaction region. Nevertheless, it is interesting to see how the classical picture mimics the quantum description. ...
PDF
... typically realized as arrays of qubits, and run-time checks are needed to detect certain error conditions. For instance, out-of-bounds checks are necessary for array accesses, and distinctness checks must be used to ensure i 6= j when applying a binary quantum operation to two qubits i and j. As is ...
... typically realized as arrays of qubits, and run-time checks are needed to detect certain error conditions. For instance, out-of-bounds checks are necessary for array accesses, and distinctness checks must be used to ensure i 6= j when applying a binary quantum operation to two qubits i and j. As is ...
Characterizing Atom Sources with Quantum Coherence
... for short arrival times between pairs of photons (coherence time).1 In contrast, a coherent source—e.g., a laser—has a correlation function value of unity for all times; and per Glauber’s quantum theory, this is expected to be true to all orders of the correlation function.2 Previous experiments by ...
... for short arrival times between pairs of photons (coherence time).1 In contrast, a coherent source—e.g., a laser—has a correlation function value of unity for all times; and per Glauber’s quantum theory, this is expected to be true to all orders of the correlation function.2 Previous experiments by ...
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.