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 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.
This is a timeline of quantum computing.
A trapped-ion quantum computer is one proposed approach to a large-scale quantum computer. Ions, or charged atomic particles, can be confined and suspended in free space using electromagnetic fields. Qubits are stored in stable electronic states of each ion, and quantum information can be transferred through the collective quantized motion of the ions in a shared trap. Lasers are applied to induce coupling between the qubit states or coupling between the internal qubit states and the external motional states.
Quantum networks form an important element of quantum computing and quantum communication systems. Quantum networks facilitate the transmission of information in the form of quantum bits, also called qubits, between physically separated quantum processors. A quantum processor is a small quantum computer being able to perform quantum logic gates on a certain number of qubits. Quantum networks work in a similar way to classical networks. The main difference is that quantum networking, like quantum computing, is better at solving certain problems, such as modeling quantum systems.
Karen L. Kavanagh is a professor of physics at Simon Fraser University in Burnaby, British Columbia, Canada, where she heads the Kavanagh Lab, a research lab working on semiconductor nanoscience.
Jonathan P. Dowling was an Irish-American researcher and professor in theoretical physics, known for his work on quantum technology, particularly for exploiting quantum entanglement for applications to quantum metrology, quantum sensing, and quantum imaging.
Within quantum technology, a quantum sensor utilizes properties of quantum mechanics, such as quantum entanglement, quantum interference, and quantum state squeezing, which have optimized precision and beat current limits in sensor technology. The field of quantum sensing deals with the design and engineering of quantum sources and quantum measurements that are able to beat the performance of any classical strategy in a number of technological applications. This can be done with photonic systems or solid state systems.
Charles Tahan is a U.S. physicist specializing in condensed matter physics and quantum information science and technology. He currently serves as the Assistant Director for Quantum Information Science (QIS) and the Director of the National Quantum Coordination Office (NQCO) within the White House Office of Science and Technology Policy. Tahan is also Chief Scientist of the National Security Agency's Laboratory for Physical Sciences.
Jeremy O'Brien is a physicist who researches in quantum optics, optical quantum metrology and quantum information science. He co-founded and serves as CEO of the quantum computing firm PsiQuantum. Formerly, he was Professorial Research Fellow in Physics and Electrical Engineering at the University of Bristol, and director of its Centre for Quantum Photonics.
The Centre for Quantum Computation (CQC) is an alliance of quantum information research groups at the University of Oxford. It was founded by Artur Ekert in 1998.
Michelle Yvonne Simmons,, is a Scientia Professor of Quantum Physics in the Faculty of Science at the University of New South Wales and has twice been an Australian Research Council Federation Fellow and is an Australian Research Council Laureate Fellow. She is the Director of the Australian Research Council Centre of Excellence for Quantum Computation & Communication Technology and is recognised internationally as the creator of the field of atomic electronics. She was the inaugural editor-in-chief of npj Quantum Information, an academic journal publishing articles in the emerging field of quantum information science. On 25 January 2018, Simmons was named as the 2018 Australian of the Year for her work and dedication to quantum information science. On 10 June 2019, Simmons was appointed an Officer of the Order of Australia (AO) in the 2019 Queen's Birthday Honours in recognition of her "distinguished service to science education as a leader in quantum and atomic electronics and as a role model."
D-Wave Two is the second commercially available quantum computer, and the successor to the first commercially available quantum computer, D-Wave One. Both computers were developed by Canadian company D-Wave Systems. The computers are not general purpose, but rather are designed for quantum annealing. Specifically, the computers are designed to use quantum annealing to solve a single type of problem known as quadratic unconstrained binary optimization. As of 2015, it was still debated whether large-scale entanglement takes place in D-Wave Two, and whether current or future generations of D-Wave computers will have any advantage over classical computers.
Christopher Roy Monroe is an American physicist and engineer in the areas of atomic, molecular, and optical physics and quantum information science, especially quantum computing. He directs one of the leading research and development efforts in ion trap quantum computing. Monroe is the Gilhuly Family Presidential Distinguished Professor of Electrical and Computer Engineering and Physics at Duke University and is College Park Professor of Physics at the University of Maryland and Fellow of the Joint Quantum Institute and Joint Center for Quantum Computer Science. He is also co-founder and chief scientist at IonQ, Inc.
Cloud-based quantum computing is the invocation of quantum emulators, simulators or processors through the cloud. Increasingly, cloud services are being looked on as the method for providing access to quantum processing. Quantum computers achieve their massive computing power by initiating quantum physics into processing power and when users are allowed access to these quantum-powered computers through the internet it is known as quantum computing within the cloud.
In quantum computing, quantum memory is the quantum-mechanical version of ordinary computer memory. Whereas ordinary memory stores information as binary states, quantum memory stores a quantum state for later retrieval. These states hold useful computational information known as qubits. Unlike the classical memory of everyday computers, the states stored in quantum memory can be in a quantum superposition, giving much more practical flexibility in quantum algorithms than classical information storage.
Stefanie Barz is a German physicist and Professor of Quantum Information and Technology at the University of Stuttgart. She studies quantum physics and quantum information in photonics.
Andrea Morello is the Scientia Professor of quantum engineering in the School of Electrical Engineering and Telecommunications at the University of New South Wales, and a Program Manager at the ARC Centre of Excellence for Quantum Computation and Communication Technology (CQC2T). Morello is the head of the Fundamental Quantum Technologies Laboratory at UNSW.
Lesley Shannon is a Canadian professor who is Chair for the Computer Engineering Option in the School of Engineering Science at Simon Fraser University. She is also the current NSERC Chair for Women in Science and Engineering for BC and Yukon. Shannon's chair operates the Westcoast Women in Engineering, Science and Technology (WWEST) program to promote equity, diversity and inclusion in STEM.
Marissa Giustina is an American physicist who is a senior research scientist at the Quantum Artificial Intelligence Lab. Her research considers the development of quantum computing and experimental tests of quantum theory.
