quantum error correction with superconducting qubits

Quantum error correction with superconducting qubits full#

Quantum error correction with superconducting qubits full#

Such processors are eminently suitable for the NISQ era approach, where the aim is to perform quantum algorithms and quantum simulations that achieve quantum advantage in the absence of full quantum error correction. Since 2012–2013, the field has climbed this ladder, including the recent demonstration of a logical qubit with a lifetime longer than any of the underlying constituent elements ( 11), operations on single logical qubits ( 12), as well as logical operations between two encoded (but not yet error-corrected) qubits ( 13).Īlthough the architectures based purely on the transmon qubit (see Section 2.1) have not yet demonstrated logical states with longer lifetimes than their constituent physical states, multiqubit systems with on the order of 10–20 qubits have been demonstrated ( 14– 18), and even larger systems with 50–100 qubits are under current development ( 19– 22). The left track (see, e.g., 9, 10) shows the progression toward building a fault-tolerant quantum computer, capable of running an arbitrarily long computation, to arbitrary precision. In Figure 1, we show two major tracks being pursued in parallel in the community. Even though the two-qubit gate fidelity in multiqubit systems is a limited metric for evaluating the maturity of a quantum computing technology, it implies a high degree of control of all aspects of the quantum processor and indicates the state of play: Superconducting qubits are well positioned to be a platform for demonstrating interesting noisy intermediate-scale quantum (NISQ) computing ( 7) protocols outside the reach of classical computers and first realizations of operations on multiple logical error-corrected qubits ( 8, 9). In 2014, the first controlled qubit–qubit interaction with fidelities greater than 0.99 in multiqubit systems was demonstrated ( 3) with the transmon qubit ( 4) variant of superconducting qubits, and since then, multiple controlled two-qubit interactions have been demonstrated with similarly high fidelities (see, e.g., 5, 6). Superconducting qubits-collective excitations in superconducting circuits-are currently one of the leading approaches for realizing quantum logic elements and quantum coherent interactions with sufficiently high controllability and low noise to be a viable candidate for implementing medium- and large-scale quantum computation. This in turn imparts the possibility to perform certain computational tasks and quantum simulations that are outside the reach of modern supercomputers ( 1, 2). The ability to control individual quantum degrees of freedom and their interactions unlocks the capability to perform quantum coherent computation. Although continued work on many aspects of this technology is certainly necessary, the pace of both conceptual and technical progress in recent years has been impressive, and here we hope to convey the excitement stemming from this progress. In this brief review, we discuss several of the recent experimental advances in qubit hardware, gate implementations, readout capabilities, early NISQ algorithm implementations, and quantum error correction using superconducting qubits.

With the recent demonstrations of multiple high-fidelity, two-qubit gates as well as operations on logical qubits in extensible superconducting qubit systems, this modality also holds promise for the longer-term goal of building larger-scale error-corrected quantum computers. The superconducting qubit modality has been used to demonstrate prototype algorithms in the noisy intermediate-scale quantum (NISQ) technology era, in which non-error-corrected qubits are used to implement quantum simulations and quantum algorithms. Superconducting qubits are leading candidates in the race to build a quantum computer capable of realizing computations beyond the reach of modern supercomputers.