Introduction to QIS
In 1982, physicist Richard Feynman proposed a computer that could perform novel calculations based around the principles of quantum mechanics. Today, SQMS researchers are exploring new approaches to develop these powerful machines.
What is a qubit?
Often represented as either a 0 or a 1, bits are the basic units of information for classical computers, such as your phone, laptop and smart devices.
Like a light switch turning on or off, the 0 or 1 is a switch within a computer. Flipping these bits is what allows a computer to operate the way it does. A series of bits can represent numbers and information to carry out a calculation. The more bits, the more powerful the computer. However, due to physical limitations, today’s computers are reaching the limit for how many bits they can process.
Quantum computers on the other hand operate with what are called quantum bits, or qubits for short. Quantum mechanics is the physics that explains the world at small length and energy scales, which is different from the physics experienced in everyday life. Instead of the switch being on or off, the “quantum switch” exhibits a quantum mechanical property called superposition, in which it is both on and off simultaneously.
In classical bits, the concept of probability does not come into play, and calculations and information are deterministic. At the heart of quantum mechanics is probability, which means that the state of a single qubit being a 0 or 1 is inherently random.
The information of one qubit can also affect the information of another qubit through a quantum mechanical concept called entanglement. This means that qubits can be intrinsically intertwined with each other. When an operator of a quantum computer affects the state of one qubit, the operator can gain information on other entangled qubits in a multi-qubit quantum computer.
SQMS researchers’ approach is to combine Josephson junction-based qubits with niobium cavities as the core building blocks of our upcoming quantum computer. Our unique approach leverages Fermilab’s world-record quality factor cavities with industry-leading quantum devices.
Quantum decoherence and error correction
Physical qubits in a quantum computing chip hold information that’s highly fragile compared to classical bits. Many factors can impact and obscure quantum information in a phenomenon called decoherence. Currently, qubits have lifetimes that are too short to perform meaningful calculations. One of the Center’s goals is to extend coherence times.
Decoherence makes performing precise calculations with few to no errors a non-trivial task. This phenomenon is an obstacle researchers need to overcome to make quantum computers a viable technology.
Many factors can create decoherence, including material imperfections, thermal vibrations, stray external electromagnetic fields and more. In order to extend the lifetimes of qubits, SQMS researchers are performing detailed studies of superconducting materials, which exhibit zero electric resistance when sufficiently cooled.
How SQMS will advance the field of QIS
SQMS research focuses on the lifetime of quantum states. This lifetime, known as coherence time, is the length of time that a qubit can effectively process information.
Understanding and mitigating the physical processes that cause decoherence and limit performance of superconducting qubits is critical to realizing next-generation quantum computers and sensors.
From materials to devices, to quantum computing and sensing platforms, to applications, the SQMS collaboration will bring revolutionary advancements in technological capabilities that will enable new scientific discovery for the quantum revolution.