#Qudit quantum error correction transversal t gate codeBy ingenuity of code design, it thus becomes possible to suppress logical decoherence arbitrarily by adding redundancy, once the physical noise level falls below some threshold. The central idea is to use quantum error correction (QEC) codes, where many physical qubits together comprise so-called logical qubits such that the logical information is distributed non-locally and thereby protected from decoherence and errors due to finite control accuracy. This roadblock towards large-scale quantum computation can be lifted with the tools of quantum fault tolerance. A fundamental challenge is to keep the quantum computation coherent, while all components of the quantum computer such as physical qubits, gate operations and measurements are inherently prone to errors. Remarkably, finite sets of native gates are sufficient to compose any operation to an arbitrary desired precision, rendering such gate sets universal. A digital quantum computer will offer a native gate set, which is comprised of the operations that can be physically executed in hardware. Quantum computers promise to efficiently solve important computational tasks that are beyond the capabilities of classical computers, such as prime factorization or the simulation of complex quantum systems. This enables entangling (darker shaded beams) but also single-qubit (lighter) gates. Single and any pair i, j of ions can be addressed simultaneously by steerable tightly focused laser beams. (c) Schematic 3D model of the ion-trap quantum processor. The magic state | H ⟩ L is prepared fault-tolerantly and subsequently teleported onto the target qubit in an arbitrary state | Ψ ⟩ L, effectively implementing a T-gate on the target qubit. Whereas the Clifford group is transversal in the color code, magic state injection can be used to realize the fault-tolerant T-gate. (b) Universal gate set consisting of Clifford gates (above dashed line) and the T-gate. The six weight-4 operators, i = 1, 2, 3, are the stabilizer generators and the weight-7 operators are logical operators Z L and X L. (a) Seven-qubit color code encoding one logical qubit in seven physical qubits. I Introduction Figure 1: QEC code, logical gates and experimental system. In combination with recently demonstrated repeated quantum error correction cycles these results open the door to error-corrected universal quantum computation. We observe the hallmark feature of fault tolerance, a superior performance compared to a non-fault-tolerant implementation. We then realize a fault-tolerant logical T-gate by injecting the magic state via teleportation from one logical qubit onto the other. We perform a logical two-qubit CNOT-gate between two instances of the seven qubit color code, and we also fault-tolerantly prepare a logical magic state. In particular, we make use of the recently introduced paradigm of flag fault tolerance, where the absence or presence of dangerous errors is heralded by usage of few ancillary ’flag’ qubits. Here, we demonstrate a fault-tolerant universal set of gates on two logical qubits in a trapped-ion quantum computer. This requires that all operations on the quantum register obey a fault-tolerant circuit design which, in general, increases the complexity of the implementation. When manipulating the logical quantum states, it is imperative that errors caused by imperfect operations do not spread uncontrollably through the quantum register. Quantum computers can be protected from noise by encoding the logical quantum information redundantly into multiple qubits using error correcting codes. Institut für Quantenoptik und Quanteninformation, Österreichische Akademie der Wissenschaften, Innsbruck, Austria Institute for Theoretical Nanoelectronics (PGI-2), Forschungszentrum Jülich, Jülich, GermanyĪlpine Quantum Technologies GmbH, Innsbruck, Austria Institute for Quantum Information, RWTH Aachen University, Aachen, Germany Institut für Experimentalphysik, Universität Innsbruck, Innsbruck, Austria
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |