Projected entangled pair states (PEPS) are a class of tensor networks that believed to represent wide variety two-dimensional physical quantum states. However, unlike their well-known one-dimensional counterparts, the matrix product (MPS), numerical simulations with PEPS suffer from instabilities can be traced back lack canonical form. The authors describe how convert into form analogous one for an MPS. It is expected this will make possible improved analytical and approaches PEPS.

Understanding charge transport in semiconductor quantum dot (QD) assemblies is important for developing the next generation of solar cells and light-harvesting devices based on QD technology. One key factors that governs such systems related to hybridization between QDs. Recent experiments have successfully synthesized molecules, arrays, by directly fusing QDs, with enhanced leading high carrier mobilities coherent band-like electronic transport. In this work, we theoretically investigate...

The capture of photoexcited hot electrons in semiconductors before they lose their excess energy to cooling is a long-standing goal photon conversion. Semiconductor nanocrystals have large electron spacings that are expected slow down relaxation by phonon emission, but nanocrystals, nevertheless, cool rapidly transfer holes. This makes the intrinsic phonon-bottleneck-limited lifetime elusive. We used combination theory and experiments probe hot-electron dynamics negatively charged cadmium...

Laser cooling is a powerful method to control molecules for applications in precision measurement, as well quantum information, many-body physics, and fundamental chemistry. However, many optically-active metal centers valence states which are promising these applications, especially difficult laser cool. In order extend the afforded by wider array of atoms, we consider use small, hypermetallic that contain multiple centers. We provide detailed analysis YbCCCa YbCCAl prototypical examples...

The giant {Mn70} and {Mn84} wheels are the largest nuclearity single-molecule magnets synthesized to date, understanding their magnetic properties poses a challenge theory. Starting from first-principles calculations, we explore excitations in these using effective spin Hamiltonians. We find that unusual geometry of superexchange pathways leads weakly coupled {Mn7} subunits carrying an S = 2 spin. spectrum exhibits hierarchy energy scales massive degeneracies, with lowest-energy arising...

We describe a practical and efficient approach to represent physically realistic long-range interactions in two-dimensional tensor network algorithms via projected entangled-pair operators (PEPOs). express the interaction as linear combination of correlation functions an auxiliary system with only nearest-neighbor interactions. To obtain smooth radially isotropic across all length scales, we map physical lattice expanded size. Our construction yields PEPO sum ancillary PEPOs, each small,...

The utilization of excited charge carriers in semiconductor nanocrystals (NCs) for optoelectronic technologies has been a long-standing goal the field nanoscience. Experimental efforts to extend lifetime have therefore principal focus. To understand limits these lifetimes, this work, we theoretically study time scales pure electron relaxation negatively charged NCs composed two prototypical materials: CdSe and CdS. We find that hot electrons lifetimes are 5 6 orders magnitude longer than CdS...

In one dimension (1D), a general decaying long-range interaction can be fit to sum of exponential interactions ${e}^{\ensuremath{-}\ensuremath{\lambda}{r}_{ij}}$ with varying exponents $\ensuremath{\lambda}$, each which represented by simple matrix product operator bond $D=3$. Using this technique, efficient and accurate simulations 1D quantum systems performed using states. However, the extension construction higher dimensions is not obvious. We report how generalize basis two three...

High-angle-of-attack flight dynamics of the X-31 configuration were studied using dynamic model test techniques. These tests identified phenomena including wing rock, spins, and departures that could dominate high-alpha behavior restrict its usable envelope. Results these have been used to design control concepts modifications minimize adverse effects phenomena. The conclusion envelope expansion aircraft will complete database against which results can be correlated.

Matrix product states (MPS) and matrix operators (MPOs) are one dimensional tensor networks that underlie the modern density renormalization group (DMRG) algorithm. The use of MPOs accounts for high level generality wide range applicability DMRG. However, current algorithms two (2D) network states, known as projected entangled-pair (PEPS), rarely employ associated 2D operators, (PEPOs), due to their computational cost conceptual complexity. To lower these barriers, we describe how...

A low-speed wind-tunnel test was conducted to determine the lateral-directional control effectiveness of a forebody jet nozzle blowing on 10% scale F-15E model. This investigation pneumatic vortex flow first its kind performed an F-15 configuration. The acquired sixcomponent force balance data in NASA Langley 30- by 60-Foot Tunnel at freestream dynamic pressure 8 psf equivalent Reynolds number per foot approximately 5.08 X 10 5. Asymmetric effective generating yawing moments through angle...

The Wright Laboratory (WL) F-16 simulation model has been re-hosted on a personal computer running unique six-degree-of-freedom environment. This contains over 1000 twodimensional aerodynamic data tables and complex flight control system (PCS) modeled by thousands of lines FORTRAN code. PCS can emulate several different configurations including standard Block 40 the Variable In-Flight Stability Aircraft (VISTA) with Multi-Axis Thrust Vectoring (MATV) in numerous modes. In addition to...

Tail rotor failure in a helicopter can be very dangerous and unstable condition. For this reason simulation model, DYN, has been formulated to analyze flight response tail steady recovery. This model uses classical theory integrates the nonlinear Euler equations of motion. DYN validated against tests several regimes all three main controls. The used for validation is McDonnell Douglas AH-64A Apache. also compares dynamic FLYRT, model. results show fairly good agreement with test, even better...

A 1/9-scale model representing a realistic next-generation fighter was tested in the NASA Langley 20-Foot Vertical Spin Tunnel. Two forebodies of different cross section were used to test seven pneumatic devices for effectiveness producing yawing moment. These included two slotted nozzles, provide baseline level, and five conformal slot devices. Although both nozzle produced effective levels moment, tangential blowing device proved be most as well being which will help reduce impact forebody...

A wind tunnel investigation was conducted in the NASA Langley 12-Foot Low-Speed to determine yaw-control effectiveness of jet nozzle blowing on a chined forebody. The results indicated that can be used forebody generate yawing moment levels up twice value maximum rudder control. In addition, this increment controllable at angles attack and beyond lift moderate sideslip angles. pointing angle cross-section were shown have pronounced impact blowing. Although effect pitching small, produced...

Recently completed high-speed rotorcraft design studies for NASA provide the basis to assess technology needs development of these aircraft. Preliminary analysis several concepts possessing helicopter-like hover characteristics and cruise capabilities in 450-kt regime, led selection two further study. The selected included rotor/wing tilt wing. Designs, based on current each, established a baseline configuration from which trade could be conducted. Technology anticipated ready application...