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 spin states can also be measured as horizontal and vertical linear 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 multiple states simultaneously, a property that is fundamental to quantum mechanics and quantum computing.
This is a timeline of quantum computing.
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 machine able to perform quantum circuits 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 is 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.
Patrick Hayden is a physicist and computer scientist active in the fields of quantum information theory and quantum computing. He is currently a professor in the Stanford University physics department and a distinguished research chair at the Perimeter Institute for Theoretical Physics. Prior to that he held a Canada Research Chair in the physics of information at McGill University. He received a B.Sc. (1998) from McGill University and won a Rhodes Scholarship to study for a D.Phil. (2001) at the University of Oxford under the supervision of Artur Ekert. In 2007 he was awarded the Sloan Research Fellowship in Computer Science. He was a Canadian Mathematical Society Public Lecturer in 2008 and received a Simons Investigator Award in 2014. Since 2015 he has been the director of the It from Qubit: Simons Collaboration on Quantum Fields, Gravity and Information.
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 an Australian quantum physicist, recognised for her foundational contributions to the field of atomic electronics.
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 was College Park Professor of Physics at the University of Maryland and Fellow of the Joint Quantum Institute and Joint Center for Quantum Computer Science until 2020 when he moved to Duke. He is also co-founder of IonQ, Inc.
Barbara M. Terhal is a theoretical physicist working in quantum information and quantum computing. She is a professor in the Delft Institute of Applied Mathematics at TU Delft, as well as leading the Terhal Group at QuTech, the Dutch institute for quantum computing and quantum internet, founded by TU Delft and the Netherlands Organisation for Applied Scientific Research (TNO). Her research concerns many areas in quantum information theory, including entanglement detection, quantum error correction, fault-tolerant quantum computing and quantum memories.
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.
Shohini Ghose is a quantum physicist and Professor of Physics and Computer Science at Wilfrid Laurier University. She has served as the president of the Canadian Association of Physicists (2019-2020), co-editor-in-chief of the Canadian Journal of Physics, and the Director of the Laurier Centre for Women in Science. She was named a 2014 TED Fellow and a 2018 TED Senior Fellow. In 2019 she appeared on the Star TV show TED Talks India Nayi Baat hosted by Shah Rukh Khan. In 2017 she was elected to the Royal Society of Canada's College of New Scholars, Artists and Scientists. Her book Clues to the Cosmos was released in India in December 2019. In 2020, she was selected as an NSERC Chair for Women in Science and Engineering.
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.
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.
