다중혈관 관상동맥 환자에서 y-문합을 이용하여 양쪽 내흉동맥만을 사용한 우회술의 조기 성적

Part I. Fundamental Concepts: 1. Introduction and overview 2. Introduction to quantum mechanics 3. Introduction to computer science Part II. Quantum Computation: 4. Quantum circuits 5. The quantum Fourier transform and its application 6. Quantum search algorithms 7. Quantum computers: physical realization Part III. Quantum Information: 8. Quantum noise and quantum operations 9. Distance measures for quantum information 10. Quantum error-correction 11. Entropy and information 12. Quantum information theory Appendices References Index.

Quantum Computation and Quantum Information

The interaction of matter and light is one of the fundamental processes occurring in nature, and its most elementary form is realized when a single atom interacts with a single photon. Reaching this regime has been a major focus of research in atomic physics and quantum optics1 for several decades and has generated the field of cavity quantum electrodynamics2,3. Here we perform an experiment in which a superconducting two-level system, playing the role of an artificial atom, is coupled to an on-chip cavity consisting of a superconducting transmission line resonator. We show that the strong coupling regime can be attained in a solid-state system, and we experimentally observe the coherent interaction of a superconducting two-level system with a single microwave photon. The concept of circuit quantum electrodynamics opens many new possibilities for studying the strong interaction of light and matter. This system can also be exploited for quantum information processing and quantum communication and may lead to new approaches for single photon generation and detection.

https://arxiv.org/pdf/cond-mat/0407325.pdf

Strong coupling of a single photon to a superconducting qubit using circuit quantum electrodynamics

The semiconductor industry has seen a remarkable miniaturization trend, driven by many scientific and technological innovations. But if this trend is to continue, and provide ever faster and cheaper computers, the size of microelectronic circuit components will soon need to reach the scale of atoms or molecules—a goal that will require conceptually new device structures. The idea that a few molecules, or even a single molecule, could be embedded between electrodes and perform the basic functions of digital electronics—rectification, amplification and storage—was first put forward in the mid-1970s. The concept is now realized for individual components, but the economic fabrication of complete circuits at the molecular level remains challenging because of the difficulty of connecting molecules to one another. A possible solution to this problem is ‘mono-molecular’ electronics, in which a single molecule will integrate the elementary functions and interconnections required for computation.

Electronics using hybrid-molecular and mono-molecular devices

We propose a realizable architecture using one-dimensional transmission line resonators to reach the strong-coupling limit of cavity quantum electrodynamics in superconducting electrical circuits. The vacuum Rabi frequency for the coupling of cavity photons to quantized excitations of an adjacent electrical circuit (qubit) can easily exceed the damping rates of both the cavity and qubit. This architecture is attractive both as a macroscopic analog of atomic physics experiments and for quantum computing and control, since it provides strong inhibition of spontaneous emission, potentially leading to greatly enhanced qubit lifetimes, allows high-fidelity quantum nondemolition measurements of the state of multiple qubits, and has a natural mechanism for entanglement of qubits separated by centimeter distances. In addition it would allow production of microwave photon states of fundamental importance for quantum communication.

https://arxiv.org/pdf/cond-mat/0402216.pdf

Cavity quantum electrodynamics for superconducting electrical circuits: An architecture for quantum computation

Nature Communications 7: Article number: 10455 (2016); Published: 27 January 2016; Updated: 3 June 2016 The affiliation details for L. Roschier are incorrect in this Article. The correct affiliation details for this author are given below: Aivon Oy, Valimotie 13A, 00380 Helsinki, Finland.

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Erratum: Nanoelectronic primary thermometry below 4 mK

We present the first experimental results on a spatially‐resolved investigation of a SET (single‐electron tunneling) circuit using the method of low temperature scanning electron microscopy. The new technique can be operated with short electron beam pulses down to 1 μs and small beam current below 1 pA, which gives the value of the charge per pulse as low as one elementary charge. By recording the circuit voltage response to the modulated electron beam irradiation as a function of the beam coordinates on the circuit, we were able to image the potentials of different parts of the circuit. For a SET‐transistor which displayed the Coulomb blockade we found evidence of memory‐effects due to charge trapping in the vicinity of one of the junctions. Further possible applications of our method for the spatially resolved study of single‐electron circuits are suggested.

Application of low temperature scanning electron microscopy for the investigation of single-electron tunneling circuits

Abstract Hybrid turnstiles have proven to generate accurate single-electron currents. The usual operation consists of applying a periodic modulation to a capacitively coupled gate electrode and requires a nonzero DC source-drain bias voltage. Under this operation, a current of the same magnitude and opposite direction can be generated by flipping the polarity of the bias. Here, we demonstrate that accurate single-electron currents can be generated under zero average bias voltage. We achieve this by applying an extra periodic modulation with twice the frequency of the gate signal and zero DC level to the source electrode. This creates a time interval, which is otherwise zero, between the crossings of tunnelling thresholds that enable single-electron tunnelling. Furthermore, we show that within this operation the current direction can be reversed by only shifting the phase of the source signal. 

/pdf/zero-average-bias-bidirectional-single-electron-current-1d2ic6fv.pdf

Zero-average Bias Bidirectional Single-electron Current Generation in a Hybrid Turnstile

Coulomb blockade electrometer based on single Cooper pair tunneling

Flexural mode vibrations of miniature piezoelectric tuning forks (TFs) are known to be highly sensitive to superfluid excitations and quantum turbulence in 3He and 4He quantum fluids, as well as to the elastic properties of solid 4He, complementing studies by large scale torsional resonators. Here, we explore the sensitivity of a TF, capable of simultaneously operating in both the flexural and torsional modes, to excitations in the normal and superfluid 4He. The torsional mode is predominantly sensitive to shear forces at the sensor–fluid interface and much less sensitive to changes in the density of the surrounding fluid when compared to the flexural mode. Although we did not reach the critical velocity for the quantum turbulence onset in the torsional mode, due to its order of magnitude higher frequency and increased acoustic damping, the torsional mode was directly sensitive to fluid excitations, linked to quantum turbulence created by the flexural mode. The combination of two dissimilar modes in a single TF sensor can provide a means to study the details of elementary excitations in quantum liquids and at interfaces between solids and quantum fluid.Flexural mode vibrations of miniature piezoelectric tuning forks (TFs) are known to be highly sensitive to superfluid excitations and quantum turbulence in 3He and 4He quantum fluids, as well as to the elastic properties of solid 4He, complementing studies by large scale torsional resonators. Here, we explore the sensitivity of a TF, capable of simultaneously operating in both the flexural and torsional modes, to excitations in the normal and superfluid 4He. The torsional mode is predominantly sensitive to shear forces at the sensor–fluid interface and much less sensitive to changes in the density of the surrounding fluid when compared to the flexural mode. Although we did not reach the critical velocity for the quantum turbulence onset in the torsional mode, due to its order of magnitude higher frequency and increased acoustic damping, the torsional mode was directly sensitive to fluid excitations, linked to quantum turbulence created by the flexural mode. The combination of two dissimilar modes in a sin...

Yu. A. Pashkin

Papers

Erratum: Nanoelectronic primary thermometry below 4 mK

Application of low temperature scanning electron microscopy for the investigation of single-electron tunneling circuits

Zero-average Bias Bidirectional Single-electron Current Generation in a Hybrid Turnstile

Coulomb blockade electrometer based on single Cooper pair tunneling

Multimode probing of superfluid 4He by tuning forks