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Pedram Roushan
Pedram Roushan is an Iranian-American physicist working at Google AI on quantum computing and quantum simulation. Biography Pedram Roushan was born in Sari, Iran, Sari, Iran in 1978 and raised in Iran. His family belonged to the Baháʼí Faith and suffered prosecution and discrimination after the Islamic Revolution. Roushan's parents were laid-off from their jobs due to their beliefs, and his father had to spend several years in hiding. In 1984 and to escape the persecution, with his family they lived in a small village close to Gilan province, where Roushan attended elementary school. In 1996, Roushan was denied access to Iranian universities. He enrolled at the ''Baháʼí Institute for Higher Education'', where he obtained a degree in civil engineering. In 2001 and with the help of the Hebrew Immigration Aid Society (HIAS), he moved to the US as a religious refugee and attended the University of Pittsburgh, where he graduated ''summa cum laude'' in 2005. He completed his Ph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sari, Iran
Sari ( ) is a city in the Central District (Sari County), Central District of Sari County, Mazandaran province, Mazandaran Province, serving as capital of the district, county, and province. Sari was the former capital of Iran for a short period and is in the north of the country, between the northern slopes of the Alborz, Alborz Mountains and southern coast of the Caspian Sea, Mazandaran Sea. Sari is the largest and most populous city of Mazandaran. History Early history Excavations in the Huto and Kamarband Caves, Hutto cave present evidence for the existence of settlements around Sari as far back as the 7th millennium BCE. The Muslim historian Hamdollah Mostowfi attributes the foundation of Sari to king Tahmuras, Tahmoures Divband of the Pishdadian Dynasty. Ferdowsi mentions the name of the city in Shahnameh, at the time of Fereydun and Manuchehr, when Manuchehr is returning to Fereydun's capital, Tamisheh in Mazandaran, after the victory over Salm (son of Fereydun), Salm an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superconducting Qubit
Superconducting quantum computing is a branch of solid state physics and quantum computing that implements superconducting electronic circuits using superconducting qubits as artificial atoms, or quantum dots. For superconducting qubits, the two logic states are the ground state and the excited state, denoted , g\rangle \text , e\rangle respectively. Research in superconducting quantum computing is conducted by companies such as Google, IBM, IMEC, BBN Technologies, Rigetti, and Intel. Many recently developed QPUs ( quantum processing units, or quantum chips) use superconducting architecture. , up to 9 fully controllable qubits are demonstrated in the 1D array, and up to 16 in 2D architecture. In October 2019, the Martinis group, partnered with Google, published an article demonstrating novel quantum supremacy, using a chip composed of 53 superconducting qubits. Background Classical computation models rely on physical implementations consistent with the laws of classical mecha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quantum Information Scientists
In physics, a quantum (: quanta) is the minimum amount of any physical entity (physical property) involved in an interaction. The fundamental notion that a property can be "quantized" is referred to as "the hypothesis of quantization". This means that the magnitude of the physical property can take on only discrete values consisting of integer multiples of one quantum. For example, a photon is a single quantum of light of a specific frequency (or of any other form of electromagnetic radiation). Similarly, the energy of an electron bound within an atom is quantized and can exist only in certain discrete values. Atoms and matter in general are stable because electrons can exist only at discrete energy levels within an atom. Quantization is one of the foundations of the much broader physics of quantum mechanics. Quantization of energy and its influence on how energy and matter interact (quantum electrodynamics) is part of the fundamental framework for understanding and describing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
21st-century American Physicists
File:1st century collage.png, From top left, clockwise: Jesus is crucified by Roman authorities in Judaea (17th century painting). Four different men ( Galba, Otho, Vitellius, and Vespasian) claim the title of Emperor within the span of a year; The Great Fire of Rome (18th-century painting) sees the destruction of two-thirds of the city, precipitating the empire's first persecution against Christians, who are blamed for the disaster; The Roman Colosseum is built and holds its inaugural games; Roman forces besiege Jerusalem during the First Jewish–Roman War (19th-century painting); The Trưng sisters lead a rebellion against the Chinese Han dynasty (anachronistic depiction); Boudica, queen of the British Iceni leads a rebellion against Rome (19th-century statue); Knife-shaped coin of the Xin dynasty., 335px rect 30 30 737 1077 Crucifixion of Jesus rect 767 30 1815 1077 Year of the Four Emperors rect 1846 30 3223 1077 Great Fire of Rome rect 30 1108 1106 2155 Boudi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
H-index
The ''h''-index is an author-level metric that measures both the productivity and citation impact of the publications, initially used for an individual scientist or scholar. The ''h''-index correlates with success indicators such as winning the Nobel Prize, being accepted for research fellowships and holding positions at top universities. The index is based on the set of the scientist's most cited papers and the number of citations that they have received in other publications. The index has more recently been applied to the productivity and impact of a scholarly journal as well as a group of scientists, such as a department or university or country. The index was suggested in 2005 by Jorge E. Hirsch, a physicist at UC San Diego, as a tool for determining theoretical physicists' relative quality and is sometimes called the Hirsch index or Hirsch number. Hirsch intended the ''h''-index to address the main disadvantages of other bibliometric indicators. The total number of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toric Code
The toric code is a topological quantum error correcting code, and an example of a stabilizer code, defined on a two-dimensional spin lattice. It is the simplest and most well studied of the quantum double models. It is also the simplest example of topological order—''Z''2 topological order (first studied in the context of ''Z''2 spin liquid in 1991). The toric code can also be considered to be a ''Z''2 lattice gauge theory in a particular limit. It was introduced by Alexei Kitaev. The toric code gets its name from its periodic boundary conditions, giving it the shape of a torus. These conditions give the model translational invariance, which is useful for analytic study. However, some experimental realizations require open boundary conditions, allowing the system to be embedded on a 2D surface. The resulting code is typically known as the planar code. This has identical behaviour to the toric code in most, but not all, cases. Error correction and computation The toric co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time Crystal
In condensed matter physics, a time crystal is a quantum system of particles whose lowest-energy state is one in which the particles are in repetitive motion. The system cannot lose energy to the environment and come to rest because it is already in its quantum ground state. Time crystals were first proposed theoretically by Frank Wilczek in 2012 as a time-based analogue to common crystals – whereas the atoms in crystals are arranged periodically in space, the atoms in a time crystal are arranged periodically in both space and time. Several different groups have demonstrated matter with stable periodic evolution in systems that are periodically driven. In terms of practical use, time crystals may one day be used as quantum computer memory. The existence of crystals in nature is a manifestation of spontaneous symmetry breaking, which occurs when the lowest-energy state of a system is less symmetrical than the equations governing the system. In the crystal ground state, the c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spin Model
A spin model is a mathematical model used in physics primarily to explain magnetism. Spin models may either be classical or quantum mechanical in nature. Spin models have been studied in quantum field theory as examples of integrable models. Spin models are also used in quantum information theory and computability theory in theoretical computer science. The theory of spin models is a far reaching and unifying topic that cuts across many fields. Introduction In ordinary materials, the magnetic dipole moments of individual atoms produce magnetic fields that cancel one another, because each dipole points in a random direction. Ferromagnetic materials below their Curie temperature, however, exhibit magnetic domains in which the atomic dipole moments are locally aligned, producing a macroscopic, non-zero magnetic field from the domain. These are the ordinary "magnets" with which we are all familiar. The study of the behavior of such "spin models" is a thriving area of research in con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Universality Class
In statistical mechanics, a universality class is a collection of mathematical models which share a single scale-invariant limit under the process of renormalization group flow. While the models within a class may differ dramatically at finite scales, their behavior will become increasingly similar as the limit scale is approached. In particular, asymptotic phenomena such as critical exponents will be the same for all models in the class. Some well-studied universality classes are the ones containing the Ising model or the percolation theory at their respective phase transition points; these are both families of classes, one for each lattice dimension. Typically, a family of universality classes will have a lower and upper critical dimension: below the lower critical dimension, the universality class becomes degenerate (this dimension is 2d for the Ising model, or for directed percolation, but 1d for undirected percolation), and above the upper critical dimension the critical exp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Noisy Intermediate-scale Quantum Era
The current state of quantum computing is referred to as the noisy intermediate-scale quantum (NISQ) era, characterized by quantum processors containing up to 1,000 qubits which are not advanced enough yet for fault-tolerance or large enough to achieve quantum advantage. These processors, which are sensitive to their environment (noisy) and prone to quantum decoherence, are not yet capable of continuous quantum error correction. This intermediate-scale is defined by the quantum volume, which is based on the moderate number of qubits and gate fidelity. The term NISQ was coined by John Preskill in 2018. According to Microsoft Azure Quantum's scheme, NISQ computation is considered level 1, the lowest of the quantum computing implementation levels. In October 2023, the 1,000 qubit mark was passed for the first time by Atom Computing's 1,180 qubit quantum processor. However, as of 2024, only two quantum processors have over 1,000 qubits, with sub-1,000 quantum processors still rem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sycamore Processor
Sycamore is a transmon superconducting quantum processor created by Google's Artificial Intelligence division. It has 53 qubits. In 2019, Sycamore completed a task in 200 seconds that Google claimed, in a ''Nature'' paper, would take a state-of-the-art supercomputer 10,000 years to finish. Thus, Google claimed to have achieved quantum supremacy. To estimate the time that would be taken by a classical supercomputer, Google ran portions of the quantum circuit simulation on Summit, one of the most powerful classical computers in the world. Later, IBM made a counter-argument, claiming that the task would take only 2.5 days on a classical system like Summit. If Google's claims are upheld, then it would represent a huge leap in computing power. In August 2020, quantum engineers working for Google reported the largest chemical simulation on a quantum computer – a Hartree–Fock approximation with Sycamore paired with a classical computer that analyzed results to provide new paramet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
