All-Microwave Leakage Reduction Units for Quantum Error Correction with Superconducting Transmon Qubits.

Minimizing leakage from computational states is a challenge when using many-level systems like superconducting quantum circuits as qubits. We realize and extend the quantum-hardware-efficient, all-microwave leakage reduction unit (LRU) for transmons in a circuit QED architecture proposed by Battistel et al. This LRU effectively reduces leakage in the second- and third-excited transmon states with up to 99% efficacy in 220 ns, with minimum impact on the qubit subspace. As a first application in the context of quantum error correction, we show how multiple simultaneous LRUs can reduce the error detection rate and suppress leakage buildup within 1% in data and ancilla qubits over 50 cycles of a weight-2 stabilizer measurement.

Mortality, morbidity, and external injuries in piglets housed in two different housing systems. II. Rearing period of weaned piglets (age 5.5-10 weeks).

Following an investigation concerning the well-being of piglets in a farrowing house, the study was continued in a rearing house. The same parameters were used: mortality, morbidity, and external injuries. Two housing systems were involved: one with a fully slatted concrete floor and one with a solid concrete floor with straw bedding. The investigation was carried out three times in each system, with approximately 550 piglets each time. Statistical analyses showed that mortality, morbidity, and frequency of external injuries were significantly higher in piglets reared in the slatted floor system than in the system with straw. The main diseases and causes of death were post-weaning enteritis and bowel oedema. Especially in the first examination (in the second week of the rearing period) the level of injury was strongly influenced by the housing system in the farrowing house. Sex, breed, origin of the piglets, litter size, and parity of the sow had no influence on the incidence of disease, but the breed had an influence on the frequency of injuries.

Mortality, morbidity, and external injuries in piglets housed in two different housing systems. I. Farrowing house.

An investigation was undertaken to study two different types of farrowing pens, use being made of well characterized veterinary parameters for the well-being of piglets. A housing system with a solid floor and straw-bedding was compared with a partly metal-slatted floor system. The veterinary parameters we used were mortality, morbidity, and external injuries in piglets. There were slight differences in mortality and morbidity rates between the two housing systems. There were big differences with regard to the piglets' 'injury-index' of the two housing systems. The straw system was more favourably. The studies show that observations of external injuries ('Method of Ekesbo') can be used to judge housing systems of piglets in the farrowing house.