Spintronics, or spin electronics, involves the study of active control and manipulation of spin degrees of freedom in solid-state systems. This article reviews the current status of this subject, including both recent advances and well-established results. The primary focus is on the basic physical principles underlying the generation of carrier spin polarization, spin dynamics, and spin-polarized transport in semiconductors and metals. Spin transport differs from charge transport in that spin is a nonconserved quantity in solids due to spin-orbit and hyperfine coupling. The authors discuss in detail spin decoherence mechanisms in metals and semiconductors. Various theories of spin injection and spin-polarized transport are applied to hybrid structures relevant to spin-based devices and fundamental studies of materials properties. Experimental work is reviewed with the emphasis on projected applications, in which external electric and magnetic fields and illumination by light will be used to control spin and charge dynamics to create new functionalities not feasible or ineffective with conventional electronics.

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Spintronics: Fundamentals and applications

We review the field of cavity optomechanics, which explores the interaction between electromagnetic radiation and nano- or micromechanical motion This review covers the basics of optical cavities and mechanical resonators, their mutual optomechanical interaction mediated by the radiation pressure force, the large variety of experimental systems which exhibit this interaction, optical measurements of mechanical motion, dynamical backaction amplification and cooling, nonlinear dynamics, multimode optomechanics, and proposals for future cavity quantum optomechanics experiments In addition, we describe the perspectives for fundamental quantum physics and for possible applications of optomechanical devices

Cavity Optomechanics

日本物理学会誌及びJournal of the Physical Society of Japanの月刊について

where A represents the magnetic vector potential, is an integral of the hydromagnetic equations. This -integral made it possible to formulate a variational principle for the force-free magnetic fields. The integral expresses the fact that motions cannot transform a given field in an entirely arbitrary different field, if the conductivity of the medium isconsidered infinite. In this paper we shall show that the full set of hydromagnetic equations admit five more integrals, besides the energy integral, if dissipative processes are absent. These integrals, as we shall presently verify, are I2 =fbHvdV, (2)

Proceedings of the National Academy of Sciences

Annals of physics

Recent initial experiments in magnetic resonance force microscopy (MRFM) have detected the magnetic force exerted by electrons and nuclei in microscopic samples. The experiments generate a force signal by modulating the sample magnetization with standard magnetic resonance techniques. Sample sizes of a few nanograms generate readily detected force signals of order ${10}^{\ensuremath{-}14}$ to ${10}^{\ensuremath{-}16}$ Newtons. This article describes the present status of MRFM technology, with particular attention to the feasibility of detecting single-electron magnetic moments, and the possible applications of MRFM in biological imaging.

Magnetic resonance force microscopy

Ligament length relationships in the moving knee

A system and method for positioning a tool relative to a patient's bone to facilitate the performance of a surgical bone alteration task. The system comprises a bone immobilization device for supporting the bone in a fixed position with respect to a reference structure, and a robot that includes a base fixed in position with respect to the reference structure. The robot also includes a mounting member, and a manipulator connected between the base and the mounting member and permitting relative movement therebetween. The tool to be positioned by the system is mounted to the mounting member. The mounting member is caused to move relative to the reference structure in response to movement commands, so that the tool can be moved to a desired task position to facilitate performance of the task. The system preferably also includes a template attachable to the mounting member, a feature of the template representing a portion of a task. Preferably, the template is secured to the mounting member, and the template is then manually manipulated such that the template feature is properly oriented with respect to the patient's bone. The template position is then recorded as a reference position that may thereafter be combined with a geometric database defining the task to determine the position of the tool. Particular embodiments for a bone immobilizer, a template and a saw guide are also described, together with a stabilizing device for the robot and a safety device for the robot base.

Robot-aided system for surgery

An orthopedic saw guide for confining the blade of a surgical saw to movement in a single plane while allowing translational and rotational movement of the blade within the plane. A pair of elongated guideplates are secured together at either end to form a partially enclosed space. The distance between the inner surfaces of the guide plates is adjustable, and is preferably adjusted to be slightly greater than the thickness of the specific blade to be used. Mounting means is provided for rigidly securing the saw guide relative to the bone, so that the plane defined by the space between the inner surfaces corresponds to the cut plane. The inner surfaces of the guide plates include guide liners that are comprised of a low-friction material. The liners may be permanently secured to the guide plates or removable and disposable. The guide plates are curved in the plane of the guide surfaces so that the saw guide can be mounted close to the end of a bone to provide maximum access to the bone with the closest possible positioning of the guide.

Orthopedic saw guide for use in a robot-aided system for surgery

The term "robot" refers to a precision mechanical device that is accurately controlled by a computer using intelligent software. The term "robotic assistance" refers to the use of such a device to aid a surgeon in the optimal conduct of a procedure, particularly one requiring specified geometrical relationships. The authors have been exploring the application of robotic assistance in situations in which accuracy and precision are required in orthopaedic surgery. The initial application concerned the planning, positioning, and orientation cuts and holes of the bone required for the femoral component of a total knee arthroplasty. A three-dimensional digitizing template allowed the surgeon to specify the desired position and orientation of the component's articular surfaces in relation to the distal femur. The robotic system used this spatial relationship, along with its knowledge of the geometry of the component selected by the surgeon, to plan the precise location of the required bone cuts and holes. Finally, the robotic assistant sequentially positioned saw and drill guides with respect to the distal femur so that the surgeon made these cuts and holes in the locations necessary for optimal component fit, position, and orientation. The robotic assistant functioned easily in the operating room environment; increased the accuracy; and decreased the time, equipment, and personnel required for the conduct of the geometrical part of this surgical procedure.

Joseph L. Garbini

Papers

Magnetic resonance force microscopy

Ligament length relationships in the moving knee

Robot-aided system for surgery

Orthopedic saw guide for use in a robot-aided system for surgery

Robotic assistance in orthopaedic surgery. A proof of principle using distal femoral arthroplasty