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Jens Eisert
Jens Eisert, born 9 October 1970, is a German physicist, ERC fellow, and professor at the Free University of Berlin. He is known for his research in quantum information science and quantum many-body theory in condensed matter physics. He has made significant contributions to entanglement theory and the study of quantum computing, as well as to the development of protocols in the quantum technologies and to the study of complex quantum systems. Work on compressed sensing quantum state tomography he has contributed to has been influential for developing notions of benchmarking and the verification of quantum devices. The concept of a graph state has become a relevant class of multi-qubit quantum states with a number of applications in quantum computing. He has contributed to realizing a first dynamical quantum simulator, in joint work with Immanuel Bloch, Ulrich Schollwöck and others, building on his work on non-equilibrium quantum physics. In quantum many-body theory, he has ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated between the Baltic and North seas to the north, and the Alps to the south; it covers an area of , with a population of almost 84 million within its 16 constituent states. Germany borders Denmark to the north, Poland and the Czech Republic to the east, Austria and Switzerland to the south, and France, Luxembourg, Belgium, and the Netherlands to the west. The nation's capital and most populous city is Berlin and its financial centre is Frankfurt; the largest urban area is the Ruhr. Various Germanic tribes have inhabited the northern parts of modern Germany since classical antiquity. A region named Germania was documented before AD 100. In 962, the Kingdom of Germany formed the bulk of the Holy Roman Empire. During the 16th ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Computing
Quantum computing is a type of computation whose operations can harness the phenomena of quantum mechanics, such as superposition, interference, and entanglement. Devices that perform quantum computations are known as quantum computers. Though current quantum computers may be too small to outperform usual (classical) computers for practical applications, larger realizations are believed to be capable of solving certain computational problems, such as integer factorization (which underlies RSA encryption), substantially faster than classical computers. The study of quantum computing is a subfield of quantum information science. There are several models of quantum computation with the most widely used being quantum circuits. Other models include the quantum Turing machine, quantum annealing, and adiabatic quantum computation. Most models are based on the quantum bit, or "qubit", which is somewhat analogous to the bit in classical computation. A qubit can be in a 1 or 0 quantum s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Entropy Of Entanglement
The entropy of entanglement (or entanglement entropy) is a measure of the degree of quantum entanglement between two subsystems constituting a two-part composite quantum system. Given a pure bipartite quantum state of the composite system, it is possible to obtain a reduced density matrix describing knowledge of the state of a subsystem. The entropy of entanglement is the Von Neumann entropy of the reduced density matrix for any of the subsystems. If it is non-zero, i.e. the subsystem is in a mixed state, it indicates the two subsystems are entangled. More mathematically; if a state describing two subsystems ''A'' and ''B'' , \Psi_\rangle=, \phi_A\rangle, \phi_B\rangleis a separable state, then the reduced density matrix \rho_A=\operatorname_B, \Psi_\rangle\langle\Psi_, =, \phi_A\rangle\langle\phi_A, is a pure state. Thus, the entropy of the state is zero. Similarly, the density matrix of ''B'' would also have 0 entropy. A reduced density matrix having a non-zero entropy is there ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Many-body Theory
The many-body problem is a general name for a vast category of physical problems pertaining to the properties of microscopic systems made of many interacting particles. ''Microscopic'' here implies that quantum mechanics has to be used to provide an accurate description of the system. ''Many'' can be anywhere from three to infinity (in the case of a practically infinite, homogeneous or periodic system, such as a crystal), although three- and four-body systems can be treated by specific means (respectively the Faddeev and Faddeev–Yakubovsky equations) and are thus sometimes separately classified as few-body systems. In general terms, while the underlying physical laws that govern the motion of each individual particle may (or may not) be simple, the study of the collection of particles can be extremely complex. In such a quantum system, the repeated interactions between particles create quantum correlations, or entanglement. As a consequence, the wave function of the system is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Immanuel Bloch
Immanuel Bloch (born 16 November 1972, Fulda) is a German experimental physicist. His research is focused on the investigation of quantum many-body systems using ultracold atomic and molecular quantum gases. Bloch is known for his work on atoms in artificial crystals of light, optical lattices, especially the first realization of a quantum phase transition from a weakly interacting superfluid to a strongly interacting Mott insulating state of matter. Career Bloch studied physics at the University of Bonn in 1995, followed by a one-year research visit to Stanford University. He obtained his PhD in 2000 working under Theodor W. Hänsch at the Ludwig-Maximilian's University in Munich. The thesis title was ''Atomlaser und Phasenkohärenz atomarer Bose-Einstein-Kondensate''. As a junior group leader, he continued in Munich and started his work on ultracold quantum gases in optical lattices. In 2003, he moved to a full professor position in experimental physics at the University of Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nature Physics
''Nature Physics'' is a monthly peer-reviewed scientific journal published by Nature Portfolio. It was first published in October 2005 (volume 1, issue 1). The chief editor is Andrea Taroni, who is a full-time professional editor employed by this journal. Scope ''Nature Physics'' publishes both pure and applied research from all areas of physics. Subject areas covered by the journal include quantum mechanics, condensed-matter physics, optics, thermodynamics, particle physics, and biophysics. Abstracting and indexing The journal is indexed in the following databases: *Chemical Abstracts Service – CASSI *Science Citation Index * Science Citation Index Expanded *Current Contents – Physical, Chemical & Earth Sciences According to the ''Journal Citation Reports'', the journal has a 2021 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Simulator
Quantum simulators permit the study of a quantum system in a programmable fashion. In this instance, simulators are special purpose devices designed to provide insight about specific physics problems. Note: This manuscript is a contribution of the US National Institute of Standards and Technology and is not subject to US copyright. Quantum simulators may be contrasted with generally programmable "digital" quantum computers, which would be capable of solving a wider class of quantum problems. A universal quantum simulator is a quantum computer proposed by Yuri Manin in 1980 and Richard Feynman in 1982. Feynman showed that a classical Turing machine would not be able to simulate a quantum effect, while his hypothetical universal quantum computer would be able to mimic needed quantum effect. A quantum system of many particles could be simulated by a quantum computer using a number of quantum bits similar to the number of particles in the original system. This has been extende ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Qubit
In quantum computing, a qubit () or quantum bit is a basic unit of quantum information—the quantum version of the classic binary bit physically realized with a two-state device. A qubit is a two-state (or two-level) quantum-mechanical system, one of the simplest quantum systems displaying the peculiarity of quantum mechanics. Examples include the spin of the electron in which the two levels can be taken as spin up and spin down; or the polarization of a single photon in which the two states can be taken to be the vertical polarization and the horizontal polarization. In a classical system, a bit would have to be in one state or the other. However, quantum mechanics allows the qubit to be in a coherent superposition of both states simultaneously, a property that is fundamental to quantum mechanics and quantum computing. Etymology The coining of the term ''qubit'' is attributed to Benjamin Schumacher. In the acknowledgments of his 1995 paper, Schumacher states that the term ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Review
''Physical Review'' is a peer-reviewed scientific journal established in 1893 by Edward Nichols. It publishes original research as well as scientific and literature reviews on all aspects of physics. It is published by the American Physical Society (APS). The journal is in its third series, and is split in several sub-journals each covering a particular field of physics. It has a sister journal, ''Physical Review Letters'', which publishes shorter articles of broader interest. History ''Physical Review'' commenced publication in July 1893, organized by Cornell University professor Edward Nichols and helped by the new president of Cornell, J. Gould Schurman. The journal was managed and edited at Cornell in upstate New York from 1893 to 1913 by Nichols, Ernest Merritt, and Frederick Bedell. The 33 volumes published during this time constitute ''Physical Review Series I''. The American Physical Society (APS), founded in 1899, took over its publication in 1913 and star ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graph State
In quantum computing, a graph state is a special type of multi-qubit state that can be represented by a graph. Each qubit is represented by a vertex of the graph, and there is an edge between every interacting pair of qubits. In particular, they are a convenient way of representing certain types of entangled states. Graph states are useful in quantum error-correcting codes, entanglement measurement and purification and for characterization of computational resources in measurement based quantum computing models. Formal definition Quantum graph states can be defined in two equivalent ways: through the notion of quantum circuits and stabilizer formalism. Quantum circuit definition Given a graph G = (V, E), with the set of vertices V and the set of edges E, the corresponding graph state is defined as : =\prod _U^ ^ where = \frac( + ) and the operator U^ is the controlled-''Z'' interaction between the two vertices (corresponding to two qubits) a and b : U^ =\left begin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Nature Research Journals
This is a list of journals published by Nature Research. These include the flagship ''Nature'' journal, the ''Nature Reviews'' series (which absorbed the former ''Nature Clinical Practice'' series in 2009), the ''npj'' series, ''Scientific Reports'' and many others. List A B C E G H I J L M N ;''Nature Reviews'' series ;''npj'' series The ''Nature Partner Journals'' series, abbreviated ''npj'', is a series of online-only, open access, journals. It was launched in April 2014 with three journals: ''npj Primary Care Respiratory Medicine'', ''npj Biofilms and Microbiomes'', and ''npj Schizophrenia''. Each journal in the series is published through a partnership between Springer Nature and a separate academic organization, foundation, or institution. O P S T References {{reflist External linksList of journalson Nature.com * Nature Research Nature Portfolio (formerly known as Nature Publishing Group and Nature Research) is a division of the intern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physical Review Letters
''Physical Review Letters'' (''PRL''), established in 1958, is a peer-reviewed, scientific journal that is published 52 times per year by the American Physical Society. As also confirmed by various measurement standards, which include the ''Journal Citation Reports'' impact factor and the journal ''h''-index proposed by Google Scholar, many physicists and other scientists consider ''Physical Review Letters'' to be one of the most prestigious journals in the field of physics. ''According to Google Scholar, PRL is the journal with the 9th journal h-index among all scientific journals'' ''PRL'' is published as a print journal, and is in electronic format, online and CD-ROM. Its focus is rapid dissemination of significant, or notable, results of fundamental research on all topics related to all fields of physics. This is accomplished by rapid publication of short reports, called "Letters". Papers are published and available electronically one article at a time. When published in s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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