Virtual Logic-The Logic of Quantum Theory.

María Luisa Dalla Chiara

S.G. Basiladze

The paper describes the general physical theory of signals, carriers of information, which supplements Shannon’s abstract classical theory and is applicable in much broader fields, including nuclear physics. It is shown that in the absence of classical noise its place should be taken by the physical threshold of signal perception for objects of both macrocosm and microcosm. The signal perception threshold allows the presence of subthreshold (virtual) signal states. For these states, Boolean algebra of logic ( A = 0/1) is transformed into the “algebraic logic” of probabilities (0 ≤ a ≤ 1). The similarity and difference of virtual states of macroand microsignals are elucidated. “Real” and “quantum” information for computers is considered briefly. The maximum information transmission rate is estimated based on physical constants.

Peter Mittelstaedt

Jonathan M. Baker, Casey Duckering, David Schuster +1 more

Fault-tolerant quantum computing is required to execute many of the most promising quantum applications. In recent years, numerous error correcting codes, such as the surface code, have emerged which are well suited for current and future limited connectivity 2-D devices. We find quantum memory, particularly resonant cavities with transmon qubits arranged in a 2.5-D architecture, can efficiently implement surface codes with around 20× fewer transmons via this work. We virtualize 2-D memory addresses by storing the code in layers of qubit memories connected to each transmon. Distributing logical qubits across many memories has minimal impact on fault tolerance and results in substantially more efficient logical operations. Virtualized logical qubit (VLQ) systems can achieve fault tolerance comparable to conventional 2-D transmon-only architectures while putting within reach a proof-of-concept experimental demonstration of around ten logical qubits, requiring only 11 transmons and 9 attached cavities.

Jin‐Lei Wu, Shi‐Lei Su

A one-step scheme to remotely create a two-atom Einstein-Podolsky-Rosen (EPR) entangled state and a quantum logic gate via exchanging the virtual photon is proposed. Two systematic atoms require no laser driving but get entangled, while the state of the auxiliary atom requiring laser driving always remains invariant. The scheme may have applications in the remote quantum information processing (QIP) tasks and quantum computation. The robustness against decoherence is demonstrated numerically and discussed in theory. In addition, the experimental issues and improvement of the scheme are also discussed.

Peter Mittelstaedt