Researchers with Duke University and IonQ, one of the leading quantum computing solution developers, have announced the development of a new operation unit in quantum computing: the quantum gate. Leveraging IonQ's ion chain-based quantum computing solutions, the new N-qubit Toffoli quantum gate expands upon the standard two-qubit gates ubiquitous in the quantum computing industry and instead allows multiple qubits to be leveraged simultaneously for the same workload, leading to more powerful and more efficient quantum circuits. Up to now, N-qubit Tofolli gates had only been theoretically demonstrated.
"No other available quantum computing architectures—not even other ion-based quantum computers—are able to utilize this new family of N-qubit gates," said IonQ co-Founder and Chief Scientist Prof. Christopher Monroe. "This is because IonQ's quantum computers uniquely feature full connectivity and a wide communication bus that allows all qubits to talk to each other simultaneously."
The qubit and gate model of current quantum computers generally employ a universal set of operations, such as single-qubit rotations and two-qubit controlled-NOT gates. However, these require that workloads be distributed amongst several, singular paired qubits (which aren't aware of other qubit states) to achieve the required acceleration, which is significantly less efficient than distributing the workload across a many-qubit (N-qubit) system. N-qubit Toffoli gates unlock the ability to perform any desired Boolean function computation in a reversible manner — which is particularly important for quantum computing operations due to their probabilistic nature.
Despite all the interesting and groundbreaking research being done in the field already, quantum computers are still a nascent technology. Coherence times (the time interval where qubits can maintain their state and hold the information being processed) are only now encroaching on human time scales - records for five-second and ten-second coherence times being achieved in other quantum architectures just this week. Imagine if your computer could only perform useable work for ten seconds at a time before you had to hit the reset button — this is the current state of quantum computing. While that particular limitation will still require an incredible amount of research to improve upon, IonQ and Duke university's research will help to increase the complexity and performance of quantum operations within already-unlocked coherence times.
"This discovery is an example of us continuing to build on the leading technical architecture we've established. It adds to the unique and powerful capabilities we are developing for quantum computing applications," said Peter Chapman, CEO at IonQ.
According to the researchers, the new N-qubit capabilities will lead to significant efficiency gains in fundamental quantum computing operations such as Grover's search algorithm, variational quantum eigensolvers (VQEs), and arithmetic operations like addition and multiplication. Being fundamental operations with applications in the fields of quantum chemistry, quantum finance, quantum machine learning, and quantum benchmarks, IonQ is betting on the new N-qubit Toffoli quantum gates to build upon the company's performance leadership in the field.