Spectrum of Andreev Bound States in a Molecule Embedded Inside a Microwave-Excited Superconducting Junction

Non-dissipative Josephson current through nanoscale superconducting constrictions is carried by spectroscopically sharp energy states, so-called Andreev bound states. Although theoretically predicted almost 40 years ago, no direct spectroscopic evidence of these Andreev bound states exists to date. We propose a novel type of spectroscopy based on embedding a superconducting constriction, formed by a single-level molecule junction, in a microwave QED cavity environment. In the electron-dressed cavity spectrum we find a polariton excitation at twice the Andreev bound state energy, and a superconducting-phase dependent ac Stark shift of the cavity frequency. Dispersive measurement of this frequency shift can be used for Andreev bound state spectroscopy.Comment: Published version; 4+ pages, 3 figure

Molecular Electronics - Modeling, Devices and Architecture

<p>Molecular electronics is an area of micro/nanoelectronics with a number of farreaching goals and challenges: denser implementation of electronic memory and logic, less expensive manufacturing, smaller or more sensitive measurement devices, selfassembly of devices and systems and, last but not least, exploring new science and applications.</p> <p>In recent years, molecular electronics has expanded into a broader field of molecular-scale electronics, partly because molecular components have to be defined in solid-state contexts via lithography and self-assembly, and effectively become hybrid devices with new and interesting properties. This thesis therefore provides an overview and critical assessment of recent experimental and theoretical development in the field of molecular-scale electronics, with focus on molecular-scale components for circuits and systems capable of performing information processing.</p> <p>The central part of this thesis is an in-depth investigation of one such device, the Nanocell, a self-assembled multi-terminal nanoelectronic switching network built from molecular (scale) linker elements with strongly non-linear and hysteretic current-voltage characteristics (IVC). The non-linearity involves negative differential resistance (NDR). The ground breaking generic new result is a demonstration, by programming from the edges without direct external access to individual links, how to configure the untrained Nanocell after fabrication and also how to reconfigure an already configured Nanocell to becoming a specific type of logic gate. The thesis also makes credible that the reconfiguration scheme is robust to most variations in the initial network topology.</p> <p>The thesis also contributes two theoretical investigations of normal and superconducting electron transport through molecular scale objects. One study demonstrates the importance of the molecular adsorption site (metal-molecule contact) for electron transport through a gold-sulfur-benzene-sulfur-gold (Au-DTB-Au) single-molecule junction. In particular, DTB and similar molecules with the terminal S-atoms buried in Au-vacancies shows prominent narrow transmission peaks close to the Fermi level, suggesting opportunities for devicing molecular switches and rectifiers. </p> <p>In the other transport investigation, it is shown that a quantum dot coupled to a phonon and positioned between two superconductors, can be used for Andreev Level spectroscopy.</p

Reconfigurable logic in nanoelectronic switching networks

We demonstrate how to configure and reconfigure a nanoelectronic nonlinear network to a universal set of logic gates by applying sequences of voltage pulses to the edges of the network. The nanoelectronic device is designed to consist of a self-assembled network of nanoparticles connected by two-terminal linker elements with hysteretic behaviour, allowing voltage-controlled switching between a linear and nonlinear current–voltage characteristic (IVC), making reconfigurable logic possible. (Some figures in this article are in colour only in the electronic version) 1

Nanocell Devices and Architecture for Configurable Computing With Molecular Electronics

We develop a method to configure a 3-D nonlinear nanoparticle-molecule network to performing ten out of twelve possible combinations of two 2-bit logic gates with shared inputs. The logic gates are based on a simple circuit with adjustable linear and fixed negative differential resistance (NDR) elements. A bistable latch for signal restoration is an integral part of this target circuit. The simulations show that conductive patterns can be formed by applying voltages on the input–output pins of the nanocell. They also show that one-link gaps (short highly resistive links) can be created within the conductive channels. Furthermore, we discuss methods for introducing NDR molecules in these gaps, a crucial element of the target circuit. The structures resulting from the simulations are put in an architectural context, in which complex functions can be realized from the individual nanocell logic gates

Mortality risk increased in colonic diverticular disease : a nationwide cohort study

Introduction: There are limited population cohort data on overall and cause-specific mortality in colonic diverticular disease.Objective: To measure overall and cause-specific mortality in colonic diverticular disease, compared to matched reference individuals and siblings.Methods: Population-based cohort study ("the ESPRESSO study") in Sweden. There were 97,850 cases with a medical diagnosis of diverticular disease (defined by international classification of disease codes) and colorectal histology identified in 1987-2017 from histopathology reports. The mortality risk between individuals with colonic diverticular disease and matched reference individuals ( n = 453/634) from the general population was determined. Cox regression models adjusted for comorbidity estimated hazard ratios (HRs) for all-cause mortality

Stoma-free survival after anastomotic leak following rectal cancer resection: worldwide cohort of 2470 patients

Background: The optimal treatment of anastomotic leak after rectal cancer resection is unclear. This worldwide cohort study aimed to provide an overview of four treatment strategies applied. Methods: Patients from 216 centres and 45 countries with anastomotic leak after rectal cancer resection between 2014 and 2018 were included. Treatment was categorized as salvage surgery, faecal diversion with passive or active (vacuum) drainage, and no primary/secondary faecal diversion. The primary outcome was 1-year stoma-free survival. In addition, passive and active drainage were compared using propensity score matching (2: 1). Results: Of 2470 evaluable patients, 388 (16.0 per cent) underwent salvage surgery, 1524 (62.0 per cent) passive drainage, 278 (11.0 per cent) active drainage, and 280 (11.0 per cent) had no faecal diversion. One-year stoma-free survival rates were 13.7, 48.3, 48.2, and 65.4 per cent respectively. Propensity score matching resulted in 556 patients with passive and 278 with active drainage. There was no statistically significant difference between these groups in 1-year stoma-free survival (OR 0.95, 95 per cent c.i. 0.66 to 1.33), with a risk difference of -1.1 (95 per cent c.i. -9.0 to 7.0) per cent. After active drainage, more patients required secondary salvage surgery (OR 2.32, 1.49 to 3.59), prolonged hospital admission (an additional 6 (95 per cent c.i. 2 to 10) days), and ICU admission (OR 1.41, 1.02 to 1.94). Mean duration of leak healing did not differ significantly (an additional 12 (-28 to 52) days). Conclusion: Primary salvage surgery or omission of faecal diversion likely correspond to the most severe and least severe leaks respectively. In patients with diverted leaks, stoma-free survival did not differ statistically between passive and active drainage, although the increased risk of secondary salvage surgery and ICU admission suggests residual confounding

Stoma-free Survival After Rectal Cancer Resection With Anastomotic Leakage: Development and Validation of a Prediction Model in a Large International Cohort.

Objective:To develop and validate a prediction model (STOMA score) for 1-year stoma-free survival in patients with rectal cancer (RC) with anastomotic leakage (AL).Background:AL after RC resection often results in a permanent stoma.Methods:This international retrospective cohort study (TENTACLE-Rectum) encompassed 216 participating centres and included patients who developed AL after RC surgery between 2014 and 2018. Clinically relevant predictors for 1-year stoma-free survival were included in uni and multivariable logistic regression models. The STOMA score was developed and internally validated in a cohort of patients operated between 2014 and 2017, with subsequent temporal validation in a 2018 cohort. The discriminative power and calibration of the models' performance were evaluated.Results:This study included 2499 patients with AL, 1954 in the development cohort and 545 in the validation cohort. Baseline characteristics were comparable. One-year stoma-free survival was 45.0% in the development cohort and 43.7% in the validation cohort. The following predictors were included in the STOMA score: sex, age, American Society of Anestesiologist classification, body mass index, clinical M-disease, neoadjuvant therapy, abdominal and transanal approach, primary defunctioning stoma, multivisceral resection, clinical setting in which AL was diagnosed, postoperative day of AL diagnosis, abdominal contamination, anastomotic defect circumference, bowel wall ischemia, anastomotic fistula, retraction, and reactivation leakage. The STOMA score showed good discrimination and calibration (c-index: 0.71, 95% CI: 0.66-0.76).Conclusions:The STOMA score consists of 18 clinically relevant factors and estimates the individual risk for 1-year stoma-free survival in patients with AL after RC surgery, which may improve patient counseling and give guidance when analyzing the efficacy of different treatment strategies in future studies