We discuss interfacing trapped atomic systems with solid-state systems such as superconducting Josephson-junction devices or nanomechanical oscillators. Such hybrid quantum systems could ease scalable quantum information processing and yield novel and profound insight into the quantum mechanics of macroscopic quantum many-body systems. We review the relevant interactions and illuminate the role of the vastly differing impedance of atomic and solid-state systems. We give some basic guidelines toward combining quantum systems, and finally, discuss some concrete proposals to interface atomic with solid-state systems.
We discuss interfacing trapped atomic systems with solid-state systems such as superconducting Josephson-junction devices or nanomechanical oscillators. Such hybrid quantum systems could ease scalable quantum information processing and yield novel and profound insight into the quantum mechanics of macroscopic quantum many-body systems. We review the relevant interactions and illuminate the role of the vastly differing impedance of atomic and solid-state systems. We give some basic guidelines toward combining quantum systems, and finally, discuss some concrete proposals to interface atomic with solid-state systems.
Hybrid quantum circuits combine two or more physical systems, with the goal of harnessing the advantages and strengths of the different systems in order to better explore new phenomena and potentially bring about novel quantum technologies. This article presents a brief overview of the progress achieved so far in the field of hybrid circuits involving atoms, spins, and solid-state devices (including superconducting and nanomechanical systems). How these circuits combine elements from atomic physics, quantum optics, condensed matter physics, and nanoscience is discussed, and different possible approaches for integrating various systems into a single circuit are presented. In particular, hybrid quantum circuits can be fabricated on a chip, facilitating their future scalability, which is crucial for building future quantum technologies, including quantum detectors, simulators, and computers.
We discuss prospects of building hybrid quantum devices involving elements of atomic and molecular physics, quantum optics and solid-state elements with the attempt to combine advantages of the respective systems in compatible experimental setups. In particular, we summarize our recent work on quantum hybrid devices and briefly discuss recent ideas for quantum networks. These include interfacing of molecular quantum memory with circuit QED, and using nanomechanical elements strongly coupled to qubits represented by electronic spins, as well as single atoms or atomic ensembles.
We discuss prospects of building hybrid quantum devices involving elements of atomic and\nmolecular physics, quantum optics and solid-state elements with the attempt to combine\nadvantages of the respective systems in compatible experimental setups. In particular, we summarize our recent work on quantum hybrid devices and briefly discuss recent ideas for quantum networks. These include interfacing of molecular quantum memory with circuit QED, and using nanomechanical elements strongly coupled to qubits represented by electronic spins, as well as single atoms or atomic ensembles.
Recent theoretical work on solid-state proposals for the implementation of quantum computation and quantum information processing is reviewed. The differences and similarities between microscopic and macroscopic qubits are highlighted and exemplified by the spin qubit proposal on one side and the superconducting qubits on the other. Before explaining the spin and supercondcuting qubits in detail, some general concepts that are relevant for both types of solid-state qubits are reviewed. The controlled production of entanglement in solid-state devices, the transport of carriers of entanglement, and entanglement detection will be discussed in the final part of this review.
The SOLID concept is to develop small solid-state hybrid systems with 3-8 qubits capable of performing elementary processing and communication of quantum information. This involves design, fabrication and investigation of combinations of qubits, oscillators, cavities, and transmission lines, creating hybrid devices interfacing different types of qubits for quantum data storage, qubit interconversion, and communication. The agenda is to provide proofs of concept, to identify roadblocks, and to stake out roads that seem particularly promising, including practical applications of quantum technologies.
We describe the design for a scalable, solid-state quantum-information-processing architecture based on the integration of GHz-frequency nanomechanical resonators with Josephson tunnel junctions, which has the potential for demonstrating a variety of single- and multiqubit operations critical to quantum computation. The computational qubits are eigenstates of large-area, current-biased Josephson junctions, manipulated and measured using strobed external circuitry. Two or more of these phase qubits are capacitively coupled to a high-quality-factor piezoelectric nanoelectromechanical disk resonator, which forms the backbone of our architecture, and which enables coherent coupling of the qubits. The integrated system is analogous to one or more few-level atoms (the Josephson junction qubits) in an electromagnetic cavity (the nanomechanical resonator). However, unlike existing approaches using atoms in electromagnetic cavities, here we can individually tune the level spacing of the ``atoms'' and control their ``electromagnetic'' interaction strength. We show theoretically that quantum states prepared in a Josephson junction can be passed to the nanomechanical resonator and stored there, and then can be passed back to the original junction or transferred to another with high fidelity. The resonator can also be used to produce maximally entangled Bell states between a pair of Josephson junctions. Many such junction-resonator complexes can be assembled in a hub-and-spoke layout, resulting in a large-scale quantum circuit. Our proposed architecture combines desirable features of both solid-state and cavity quantum electrodynamics approaches, and could make quantum-information processing possible in a scalable, solid-state environment.