Author
Craig S. Lent
Other affiliations: Arizona State University, University of Minnesota
Bio: Craig S. Lent is an academic researcher from University of Notre Dame. The author has contributed to research in topics: Quantum dot cellular automaton & Quantum cellular automaton. The author has an hindex of 54, co-authored 178 publications receiving 14153 citations. Previous affiliations of Craig S. Lent include Arizona State University & University of Minnesota.
Papers published on a yearly basis
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TL;DR: In this article, the authors proposed a new paradigm for computing with cellular automata (CAS) composed of arrays of quantum devices, which is called edge driven computing (EDC), where input, output and power are delivered at the edge of the CA array only; no direct flow of information or energy to internal cells is required.
Abstract: The authors formulate a new paradigm for computing with cellular automata (CAS) composed of arrays of quantum devices-quantum cellular automata. Computing in such a paradigm is edge driven. Input, output, and power are delivered at the edge of the CA array only; no direct flow of information or energy to internal cells is required. Computing in this paradigm is also computing with the ground state. The architecture is so designed that the ground-state configuration of the array, subject to boundary conditions determined by the input, yields the computational result. The authors propose a specific realization of these ideas using two-electron cells composed of quantum dots. The charge density in the cell is very highly polarized (aligned) along one of the two cell axes, suggestive of a two-state CA. The polarization of one cell induces a polarization in a neighboring cell through the Coulomb interaction in a very non-linear fashion. Quantum cellular automata can perform useful computing. The authors show that AND gates, OR gates, and inverters can be constructed and interconnected.
1,540 citations
TL;DR: This work examines the possible implementation of logic devices using coupled quantum dot cells, which use these cells to design inverters, programmable logic gates, dedicated AND and OR gates, and non‐interfering wire crossings.
Abstract: We examine the possible implementation of logic devices using coupled quantum dot cells. Each quantum cell contains two electrons which interact Coulombically with neighboring cells. The charge distribution in each cell tends to align along one of two perpendicular axes, which allows the encoding of binary information using the state of the cell. The state of each cell is affected in a very nonlinear way by the states of its neighbors. A line of these cells can be used to transmit binary information. We use these cells to design inverters, programmable logic gates, dedicated AND and OR gates, and non‐interfering wire crossings. Complex arrays are simulated which implement the exclusive‐OR function and a single‐bit full adder.
1,149 citations
01 Apr 1997
TL;DR: A new adiabatic switching paradigm is developed which permits clocked control, eliminates metastability problems, and enables a pipelined architecture.
Abstract: We describe a paradigm for computing with interacting quantum dots, quantum-dot cellular automata (QCA). We show how arrays of quantum-dot cells could be used to perform useful computations. A new adiabatic switching paradigm is developed which permits clocked control, eliminates metastability problems, and enables a pipelined architecture.
1,127 citations
TL;DR: A functioning logic gate based on quantum-dot cellular automata is presented, where digital data are encoded in the positions of only two electrons, and theoretical simulations of the logic gate output characteristics are in excellent agreement with experiment.
Abstract: A functioning logic gate based on quantum-dot cellular automata is presented, where digital data are encoded in the positions of only two electrons. The logic gate consists of a cell, composed of four dots connected in a ring by tunnel junctions, and two single-dot electrometers. The device is operated by applying inputs to the gates of the cell. The logic AND and OR operations are verified using the electrometer outputs. Theoretical simulations of the logic gate output characteristics are in excellent agreement with experiment.
594 citations
TL;DR: In this paper, a basic cell of the quantum-dot cellular automata, a transistorless approach to computation that addresses the issues of device density, interconnection, and power dissipation, is presented.
Abstract: This paper presents an experimental demonstration of a basic cell of the quantum-dot cellular automata, a transistorless approach to computation that addresses the issues of device density, interconnection, and power dissipation. The device under study was composed of four metal dots, connected with tunnel junctions and capacitors, and operated at <50 mK. Operation was evidenced by switching of a single electron between output dots controlled by a single electron switching in input dots, demonstrating a nonlinear, bistable response.
591 citations
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7,711 citations
TL;DR: In this article, solution phase syntheses and size-selective separation methods to prepare semiconductor and metal nanocrystals, tunable in size from ∼1 to 20 nm and monodisperse to ≤ 5%, are presented.
Abstract: ▪ Abstract Solution phase syntheses and size-selective separation methods to prepare semiconductor and metal nanocrystals, tunable in size from ∼1 to 20 nm and monodisperse to ≤5%, are presented. Preparation of monodisperse samples enables systematic characterization of the structural, electronic, and optical properties of materials as they evolve from molecular to bulk in the nanometer size range. Sample uniformity makes it possible to manipulate nanocrystals into close-packed, glassy, and ordered nanocrystal assemblies (superlattices, colloidal crystals, supercrystals). Rigorous structural characterization is critical to understanding the electronic and optical properties of both nanocrystals and their assemblies. At inter-particle separations 5–100 A, dipole-dipole interactions lead to energy transfer between neighboring nanocrystals, and electronic tunneling between proximal nanocrystals gives rise to dark and photoconductivity. At separations <5 A, exchange interactions cause otherwise insulating ass...
4,116 citations
TL;DR: In this paper, the basic physical processes involved in the nucleation and growth of thin films of materials on solid surfaces are described, and the relationships between the thermodynamics of adsorption and the kinetics of crystal growth are explored in general terms.
Abstract: The purpose of this article is to describe the basic physical processes involved in the nucleation and growth of thin films of materials on solid surfaces. In this introduction the three modes of crystal growth which are thought to occur on surfaces in the absence of interdiffusion are described, and the relationships between the thermodynamics of adsorption and the kinetics of crystal growth are explored in general terms. This is followed by a brief review of atomistic nucleation theory, explaining the relations of such theories to experimental observables. In the next three sections, recent experimental examples of these three growth modes are given, which are interpreted where possible in terms of nucleation and growth theory. The last section discusses observations on the shapes of growing crystallites and the relation of such observations to nucleation and surface diffusion processes.
2,456 citations
TL;DR: This work presents an autonomous ordering and assembly of atoms and molecules on atomically well-defined surfaces that combines ease of fabrication with exquisite control over the shape, composition and mesoscale organization of the surface structures formed.
Abstract: The fabrication methods of the microelectronics industry have been refined to produce ever smaller devices, but will soon reach their fundamental limits. A promising alternative route to even smaller functional systems with nanometre dimensions is the autonomous ordering and assembly of atoms and molecules on atomically well-defined surfaces. This approach combines ease of fabrication with exquisite control over the shape, composition and mesoscale organization of the surface structures formed. Once the mechanisms controlling the self-ordering phenomena are fully understood, the self-assembly and growth processes can be steered to create a wide range of surface nanostructures from metallic, semiconducting and molecular materials.
2,013 citations
TL;DR: “Spintronics,” in which both the spin and charge of electrons are used for logic and memory operations, promises an alternate route to traditional semiconductor electronics.
Abstract: “Spintronics,” in which both the spin and charge of electrons are used for logic and memory operations, promises an alternate route to traditional semiconductor electronics. A complete logic architecture can be constructed, which uses planar magnetic wires that are less than a micrometer in width. Logical NOT, logical AND, signal fan-out, and signal cross-over elements each have a simple geometric design, and they can be integrated together into one circuit. An additional element for data input allows information to be written to domain-wall logic circuits.
1,955 citations