Encoded Silicon Qubits: A High-Performance & Scalable Platform for Quantum Computing
For quantum computers to achieve their promise, regardless of the qubit technology, significant improvements to both performance and scale are required. Quantum-dot-based qubits in silicon have recently enjoyed dramatic advances in fabrication and control techniques. The “exchange-only” modality is of particular interest, as it avoids control elements that are difficult to scale such as microwave fields, photonics, or ferromagnetic gradients. In this control scheme, the entirety of quantum computation may be performed using only asynchronous, baseband voltage p
Repeated Quantum Error Correction in a Distance-Three Surface Code with Superconducting Circuits
Quantum computers hold the promise of solving computational problems which are intractable using conventional methods. For fault-tolerant operation quantum computers must correct errors occurring due to unavoidable decoherence and limited control accuracy. Here, we demonstrate quantum error correction using the surface code, which is known for its exceptionally high tolerance to errors. Using 17 physical qubits in a superconducting circuit we encode quantum information in a distance-three logical qubit building up on recent distance-two error detection experiments [1].
Distinguishing between quantum and classical Markovian dephasing dissipation
Understanding whether dissipation in an open quantum system is truly quantum is a question of both fundamental and practical interest. We consider a general model of n qubits subject to correlated Markovian dephasing, and present a sufficient condition for when bath-induced dissipation can generate system entanglement and hence must be considered quantum. Surprisingly, we find that the presence or absence of time-reversal symmetry (TRS) plays a crucial role: broken TRS is required for dissipative entanglement generation.
Exact bosonization in all dimensions and the duality between fermionic SPT and higher-group bosonic SPT phases
The first part of this talk will introduce generalized Jordan–Wigner transformation on arbitrary triangulation of any manifold in 2d, 3d, and general dimensions. This gives a duality between all fermionic systems and a new class of Z2 lattice gauge theories. This map preserves the locality and has an explicit dependence on the second Stiefel–Whitney class and a choice of spin structure on the manifold.