Deterministic quantum teleportation with feed-forward in a solid state system

Abstract

Engineered macroscopic quantum systems based on superconducting electronic circuits are attractive for experimentally exploring diverse questions in quantum information science. At the current state of the art, quantum bits (qubits) are fabricated, initialized, controlled, read out and coupled to each other in simple circuits. This enables the realization of basic logic gates, the creation of complex entangled states and the demonstration of algorithms or error correction. Using different variants of low-noise parametric amplifiers, dispersive quantum non-demolition single-shot readout of single-qubit states with high fidelity has enabled continuous and discrete feedback control of single qubits. Here we realize full deterministic quantum teleportation with feed-forward in a chip-based superconducting circuit architecture. We use a set of two parametric amplifiers for both joint two-qubit and individual qubit single-shot readout, combined with flexible real-time digital electronics. Our device uses a crossed quantum bus technology that allows us to create complex networks with arbitrary connecting topology in a planar architecture. The deterministic teleportation process succeeds with order unit probability for any input state, as we prepare maximally entangled two-qubit states as a resource and distinguish all Bell states in a single two-qubit measurement with high efficiency and high fidelity. We teleport quantum states between two macroscopic systems separated by 6 mm at a rate of 10(4) s(-1), exceeding other reported implementations. The low transmission loss of superconducting waveguides is likely to enable the range of this and other schemes to be extended to significantly larger distances, enabling tests of non-locality and the realization of elements for quantum communication at microwave frequencies. The demonstrated feed-forward may also find application in error correction schemes.

Quantum teleportation from a propagating photon to a solid-state spin qubit

“…Over the last decade, both probabilistic/heralded 1,5-8 and deterministic teleportation [9][10][11][12][13] have been demonstrated in various quantum systems. The realization of quantum teleportation between a propagating photon and a single semiconductor spin that we describe in this paper closely builds on prior demonstrations of photon-stationary qubit interfaces in collective atomic excitations in atomic vapours 14,15 and in doped crystals 16,17 , as well as in single trapped atoms 18,19 .…”

Measurement and control of quasiparticle dynamics in a superconducting qubit

“…S uperconducting quantum circuits have made rapid progress 1 in realizing increasingly sophisticated quantum states 2,3 and operations 4,5 with high fidelity. Excitations of the superconductor, or quasiparticles (QPs), can limit their performance by causing relaxation and decoherence, with the rate approximately proportional to the QP density 6 .…”

Quantum-teleportation experiments turn 20

“…Most experiments have tried to maximize the last of these distances because this is the easiest to achieve -although one experiment considered all three distances 12 . Other work has suggested exploiting teleportation over extremely short distances (a few millimetres), but using a huge number of quantum states 13 . This could tremendously speed up information processing in quantum computers compared with what would otherwise be possible.…”