User:Tyttcfm/sandbox

thearticlegoeshere Proper way for interlanguage link

Overview
First paragraph general technical overview. Second paragraph chronological story of proposals and experimental realizations, key people.

Organize the following headers into relatively chronological as well, in terms of when the first proposals or landmark experiments were done

http://pettagroup.princeton.edu/cqed.html

http://www.jst.go.jp/erato/nakamura_mqm/english/project_overview/p02.html

Hybrid quantum systems are circuit quantum electrodynamical systems interacting with other quantum systems in order to address issues that exist in the individual systems but not in the hybrid systems. For instance, the scalability and individual addressability of solid-state systems combined with the ....

Some examples include Rydberg atoms, ..........., and semiconductor quantum dots combining with solid-state systems to unlock "the long coherence times available in microscopic quantum systems with the strong interactions and integration available in solid state systems... [to allow] for strong interactions with control fields and thus fast manipulation of the quantum state of a system." ^get academic explanation as well, something from journal. Maybe remove since it implies the only qubit you can use is superconducting

http://www.pnas.org/content/112/13/3866 good overview paper.

Overview news, Nature

SC, trapped ion/electron, topological, NV Centers are all used to interface with these other systems. Make it clear and general.

"The hybrid system therefore implements a “quantum transducer,” where the quantum reality (i.e., superpositions and entanglement) of small objects is extended to include the larger object." (Proposing using trapped electrons instead of trapped ions as the qubit in hybrid quantum systems)

Tons of great figures and tables, but no permissions for reuse.

Chapter of a book about Hybrid Quantum Computing, https://books.google.ch/books?hl=en&lr=&id=PTfpCAAAQBAJ&oi=fnd&pg=PA37&ots=cTQZ-5YjM4&sig=m8JH7e2pFmTG8H-1cqftaZlhrv8#v=onepage

Overview, includes polar molecules (Rydberg atoms, trapped ions which allow optical interface) and nanomechanical (phonons, mechanical oscillator).

Section in this paper on hybrid proposals "to couple ideas from proven approaches to quantum computing (cavity QED, trapped ions and trapped atoms) with the benefits offered by solid-state implementations."

"The recent development of new cooling and trapping technologies for the production of cold and ultra-cold molecules opens new perspectives for the manipulations of molecules on a quantum level in a way that currently is only achieved for atomic systems. In contrast to atoms or ions, the rotational degrees of freedom of molecules in combination with electric dipole moments provide additional features which might be exploited for trapping and quantum information processing with static and microwave electric fields. Due to the large dipole moments of μ ∼ 5 Debye, polar molecules interact strongly with electric fields, which is a key property for coherent interactions solid state devices such as superconducting microwave cavities or charge qubits."

Good news article explainer by Nature https://www.nature.com/nphys/journal/v2/n9/full/nphys403.html

Should trapped ions, neutral atoms be put into "polar molecules" header?
"Mesoscopic solid-state systems such as Josephson junctions and quantum dots feature robust control techniques using local electrical signals and self-evident scaling; however, in general the quantum states decohere rapidly. In contrast, quantum optical systems based on trapped ions and neutral atoms exhibit much better coherence properties, but their miniaturization and integration with electrical circuits remains a challenge. Here we describe methods for the integration of a single-particle system—an isolated polar molecule—with mesoscopic solid-state devices in a way that produces robust, coherent, quantum-level control."

Rydberg atoms
As a particular qubit example, we consider an ensemble of ultracold 87Rb atoms and the hyperfine transition between... states at a frequency of 6.83 GHz, which is ideally suited for a [superconducting coplanar waveguide resonator].

Topological
https://physics.aps.org/synopsis-for/10.1103/PhysRevLett.106.130504

Carbon nanotubes
SC flux qubit Diamond NV center

Spin
Really early proposal.

Transmon with spin ensemble consisting of NV centers in diamond

Molecular cloud of cold polar molecules coupled to cQED system

SC flux qubit to electron spin ensemble (in th form of NV centers) in diamond.

SC phase qubit to spin NV centers in diamond.

Nitrogen-vacancy (NV) centers in diamond are used as the spin ensemble in our approach because of their long coherence times, even at room temperature. Therefore such a spin ensemble can be used as a quantum memory in the hybrid quantum circuit.

Nanomechanical
Proposal for coupling of nanomechanical resonator to SC flux qubit, discuss experimental realization.

"A promising approach is to combine long-lived atomic states with the accessible electrical degrees of freedom in superconducting cavities and quantum bits (qubits). Here we integrate circuit cavity quantum electrodynamics with phonons."