Quantum Computing | What Are Qubits?

Quantum computing is a new and rapidly growing field that has the potential to revolutionize the way we process and store information. Unlike classical computing, which relies on bits of information that can exist in only one of two states (0 or 1), quantum computing uses quantum bits, or qubits, that can exist in multiple states at once. This allows quantum computers to perform certain types of calculations much faster than classical computers. The basics of quantum computing can be difficult to understand, but a good starting point is to think of a qubit as a coin that can be flipped to land on either heads or tails. In classical computing, a bit is like a coin that has already landed on either heads or tails, and the only thing you can do is look at the result. In quantum computing, however, a qubit can be in a superposition of states, meaning that it can be both heads and tails at the same time. This allows a quantum computer to perform multiple calculations simultaneously, which is known as parallel processing.

The history of quantum computing can be traced back to the early 20th century, when scientists first began to understand the strange behavior of subatomic particles.

• 1928: physicist Paul Dirac proposed the mathematical form of quantum mechanics, laying the foundation for the study of quantum systems.
• 1935: Einstein, Boris Podolsky, and Nathan Rosen published a paper that introduced the concept of entanglement, which would later become a key aspect of quantum computing.
• 1940s: Physicist Richard Feynman proposed the idea of using quantum systems to perform calculations, setting the stage for the development of quantum computing.
• 1980s: The first quantum algorithm, Shor’s algorithm, was developed by mathematician Peter Shor. It was able to factorize large numbers exponentially faster than any known classical algorithm.
• 1989: David Deutsch proposed the concept of a “quantum Turing machine,” the theoretical foundation for a quantum computer.
• 1998: The first working prototype of a quantum computer, the D-Wave One, was built by Canadian company D-Wave Systems.
• 2001: A team led by physicist Isaac Chuang at IBM’s Almaden Research Center successfully built and measured a 7-qubit quantum computer.
• 2005: A team led by physicist John Martinis at the University of California, Santa Barbara, built a 9-qubit superconducting quantum processor.
• 2007: D-Wave Systems announces the world’s first commercially available quantum computer.
• 2011: A team at the University of Bristol demonstrated the first two-qubit operation on a silicon chip, paving the way for the integration of quantum computing with existing semiconductor technology.
• 2016: Google’s quantum computing lab, Google AI Quantum, announced the development of a chip with 9 superconducting qubits.
• 2017: IBM made a 20 qubits processor available on their cloud platform, making it accessible to researchers and businesses around the world.
• 2018: Google announced that its quantum computer, named “Bristlecone,” had achieved “quantum supremacy,” by solving a problem that would take the world’s most powerful supercomputer over 10,000 years to solve in under 200 seconds.
• 2019: IBM announced the release of the IBM Q System One, the world’s first integrated quantum computing system for commercial use.
• 2020: Google achieved a new milestone by developing a 53-qubit quantum computer, named Sycamore, which was able to perform a calculation in 200 seconds that would take the world’s most powerful supercomputer 10,000 years to complete.
• 2021: The worldwide effort to develop quantum computing is still ongoing, with companies such as IBM, Google, Microsoft, Alibaba, and Rigetti Computing among others are actively investing in the field and working on building more powerful and robust quantum computers.

Google’s quantum computer, named “Bristlecone,” is a major breakthrough in the field of quantum computing. The computer is built using superconducting qubits, which are made from superconducting materials that can conduct electricity with zero resistance. This allows for very precise control of the qubits, which is essential for performing complex calculations. One of the key features of Bristlecone is its large number of qubits. The computer has 72 qubits, which is more than any other quantum computer currently in existence. This large number of qubits allows Bristlecone to perform calculations that would be impossible for classical computers to complete in a reasonable amount of time. In 2018, Google announced that its quantum computer, Bristlecone, had achieved “quantum supremacy,” by solving a problem that would take the world’s most powerful supercomputer over 10,000 years to solve in under 200 seconds. This was a significant milestone in the field of quantum computing, as it demonstrated the power of quantum computers to solve problems that are beyond the capabilities of classical computers. Bristlecone is also notable for its error correction capabilities. As we know, the key challenge with quantum computing is the qubits’ sensitivity to their environment, which leads to errors in the calculations. Google has developed a method of error correction that allows Bristlecone to perform calculations with a high degree of accuracy, even in the presence of errors.

Another important aspect of Bristlecone is that it is built using superconducting qubits, which allows for a high level of control over the qubits. This is essential for performing complex calculations, as it allows the qubits to be precisely manipulated to perform the calculation. Google’s team has developed a special control system for the qubits that enables them to perform a wide variety of quantum gates, which are the basic building blocks of quantum algorithms. Google’s Bristlecone is also designed to be easily scalable, which means that it can be expanded to include more qubits in the future. This is an important consideration, as the number of qubits is directly related to the power of the quantum computer. As more qubits are added to the computer, it will be able to perform more complex calculations and solve more challenging problems. Google has also been working on developing software that can run on quantum computers like Bristlecone. The company has developed a programming language called “OpenFermion” that can be used to program quantum algorithms for use on Bristlecone and other quantum computers.

Despite its impressive capabilities, Bristlecone is not yet ready for commercial use. Google has said that it is still working on improving the computer’s performance and error correction capabilities. However, the company has also stated that it plans to make Bristlecone available to researchers and businesses through its cloud computing platform, Google Cloud.

One of the key concepts in quantum computing is entanglement, which occurs when two or more qubits are connected in such a way that the state of one qubit is dependent on the state of the other qubits. This allows quantum computers to perform certain types of calculations much faster than classical computers. For example, a quantum computer can perform a calculation that would take a classical computer billions of years to complete in just a few minutes. Another important concept in quantum computing is quantum teleportation. This refers to the ability to transfer the state of a qubit from one location to another without physically moving the qubit. This is made possible by the phenomenon of quantum entanglement, which allows two qubits to be connected in such a way that the state of one qubit is dependent on the state of the other qubit.

The development of quantum computing technology is still in its infancy, but there are several companies and organizations that are currently working on building practical quantum computers. Some of the most notable companies include Google, IBM, and Microsoft. Each of these companies has its own approach to building a quantum computer, but all are focused on using superconducting qubits. Superconducting qubits are the most common type of qubits used in quantum computing today. These qubits are made from superconducting materials, which are materials that can conduct electricity with zero resistance. This allows for very precise control of the qubits, which is essential for performing complex calculations.

Another type of qubits that is being researched is topological qubits. These qubits are made from materials that have a special type of electrical conductivity known as topological protection. This means that the qubits are able to maintain their state even in the presence of outside interference. This makes topological qubits more robust and less susceptible to errors. Quantum computing has the potential to revolutionize many industries, including finance, healthcare, and transportation. In finance, for example, quantum computers could be used to perform complex financial calculations much faster than classical computers. This could lead to more efficient markets and reduced risk for investors. In healthcare, quantum computing could be used to analyze large amounts of medical data to identify new treatments and cures for diseases. In transportation, quantum computing could be used to optimize logistics and supply chain management.

Despite the potential benefits of quantum computing, there are also some concerns. One concern is that quantum computers could be used to break encryption, which would have serious implications for security and privacy. Another concern is that quantum computers could be used to create new weapons or other military technologies. It’s important to note that while the history of quantum computing is relatively short, it has been a rapid progression, with the field evolving quickly and new breakthroughs happening regularly. The future looks promising for quantum computing, as researchers and companies continue to make progress in developing practical and useful quantum computers that can solve complex problems that classical computers can’t. In conclusion, quantum computing is a rapidly developing field that has the potential to revolutionize many industries.