Cross-coupling effects in circuit-QED stimulated Raman adiabatic passage

Stimulated Raman adiabatic passage is a quantum protocol that can be used for robust state preparation in a three-level system. It has been commonly employed in quantum optics, but recently this technique has drawn attention also in circuit quantum electrodynamics. The protocol relies on two slowly varying drive pulses that couple the initial and the target state via an intermediate state, which remains unpopulated. Here we study the detrimental effect of the parasitic couplings of the drives into transitions other than those required by the protocol. The effect is most prominent in systems with almost harmonic energy level structure, such as the transmon. We show that under these conditions in the presence of decoherence there exists an optimal STIRAP amplitude for population transfer.Comment: Will be published in proceedings for 28th International Conference for Low Temperature Physic

Experimental state control by fast non-Abelian holonomic gates with a superconducting qutrit

Quantum state manipulation with gates based on geometric phases acquired during cyclic operations promises inherent fault-tolerance and resilience to local fluctuations in the control parameters. Here we create a general non-Abelian and non-adiabatic holonomic gate acting in the $(\ket{0},\ket{2})$ subspace of a three-level transmon fabricated in a fully coplanar design. Experimentally, this is realized by simultaneously coupling the first two transitions by microwave pulses with amplitudes and phases defined such that the condition of parallel transport is fulfilled. We demonstrate the creation of arbitrary superpositions in this subspace by changing the amplitudes of the pulses and the relative phase between them. We use two-photon pulses acting in the holonomic subspace to reveal the coherence of the state created by the geometric gate pulses and to prepare different superposition states. We also test the action of holonomic NOT and Hadamard gates on superpositions in the $(\ket{0},\ket{2})$ subspace

Pressure of the Standard Model Near the Electroweak Phase Transition

We extend our previous determination of the thermodynamic pressure of the Standard Model so that the result can be applied down to temperatures corresponding to the electroweak crossover. This requires a further resummation which can be cleanly organised within the effective theory framework. The result allows for a precise determination of the expansion rate of the Universe for temperatures around the electroweak crossover.Comment: 16 pages, 6 figures. v2: published versio

Pressure of the Standard Model at High Temperatures

We compute the pressure of the standard model at high temperatures in the symmetric phase to three loops, or to O(g^5) in all coupling constants. We find that the terms of the perturbative expansion in the SU(2) + Higgs sector decrease monotonically with increasing order, but the large values of the strong coupling constant g_s and the Yukawa coupling of the top quark g_Y make the expansion in the full theory converge more slowly. The final result is observed to be about 10% smaller than the ideal gas pressure commonly used in cosmological calculations.Comment: 30 pages, 4 figures. v2: one reference added, minor revisions, accepted for publication in JHE

Mesonic screening masses at high temperature and finite density

We compute the first perturbative correction to the static correlation lengths of light quark bilinears in hot QCD with finite quark chemical potentials. The correction is small and positive, with mu-dependence depending on the relative sign of chemical potentials and the number of dynamical flavors. The computation is carried out using a three-dimensional effective theory for the lowest fermionic Matsubara mode. We also compute the full correlator in free theory and find a rather complicated general mu-dependence at shorter distances. Finally, rough comparisons with lattice simulations are discussed.Comment: 24 pages, 5 figures, JHEP style. Minor corrections and clarifications, version to appear in JHE

Quantum-enhanced magnetometry by phase estimation algorithms with a single artificial atom

Phase estimation algorithms are key protocols in quantum information processing. Besides applications in quantum computing, they can also be employed in metrology as they allow for fast extraction of information stored in the quantum state of a system. Here, we implement two suitably modified phase estimation procedures, the Kitaev and the semiclassical Fourier-transform algorithms, using an artificial atom realized with a superconducting transmon circuit. We demonstrate that both algorithms yield a flux sensitivity exceeding the classical shot-noise limit of the device, allowing one to approach the Heisenberg limit. Our experiment paves the way for the use of superconducting qubits as metrological devices which are potentially able to outperform the best existing flux sensors with a sensitivity enhanced by few orders of magnitude

The Relationship between Dietary Habits and Work Engagement among Female Finnish Municipal Employees

Background: Work engagement reflects work-related well-being. It is positively associated with health, life satisfaction, work efficiency, income level, and occupational prospects. However, little is known about the relationship between work engagement and diet. Methods: A cross-sectional study was conducted among female Finnish municipal employees (n = 630) in 2015. Work engagement was assessed using the Utrecht Work Engagement Index. The consumption of healthy and unhealthy food items was determined using a food frequency questionnaire. Sociodemographic factors, health behaviors, depressive and anxiety symptoms were assessed with self-administrated questionnaires. Results: Work engagement had a positive relationship with the daily consumption of healthy food items. This association remained significant even after adjusting for age, education years, financial situation, and physical activity. The frequency of consuming unhealthy food items showed no relationship with work engagement. Anxiety and depressive symptoms decreased linearly with the greater consumption of healthy foods. Conclusion: Frequent consumption of healthy food items is associated with higher work engagement, irrespectively of the consumption of unhealthy nutrients. These results encourage health care professionals to recommend healthy food items instead of forbidding unhealthy food, as well as employers to support healthy dietary habits among employees

The Relationship between Dietary Habits and Work Engagement among Female Finnish Municipal Employees

Background: Work engagement reflects work-related well-being. It is positively associated with health, life satisfaction, work efficiency, income level, and occupational prospects. However, little is known about the relationship between work engagement and diet. Methods: A cross-sectional study was conducted among female Finnish municipal employees (n = 630) in 2015. Work engagement was assessed using the Utrecht Work Engagement Index. The consumption of healthy and unhealthy food items was determined using a food frequency questionnaire. Sociodemographic factors, health behaviors, depressive and anxiety symptoms were assessed with self-administrated questionnaires. Results: Work engagement had a positive relationship with the daily consumption of healthy food items. This association remained significant even after adjusting for age, education years, financial situation, and physical activity. The frequency of consuming unhealthy food items showed no relationship with work engagement. Anxiety and depressive symptoms decreased linearly with the greater consumption of healthy foods. Conclusion: Frequent consumption of healthy food items is associated with higher work engagement, irrespectively of the consumption of unhealthy nutrients. These results encourage health care professionals to recommend healthy food items instead of forbidding unhealthy food, as well as employers to support healthy dietary habits among employees

Bisphosphonate treatment in children with acute lymphoblastic leukemia and osteonecrosis - radiological and clinical findings in a national cohort

Background: Osteonecrosis (ON) is a recognized complication of childhood ALL, but its optimal management remains unestablished. This study evaluated the effect of bisphosphonate (BP) treatment on the evolution of ON lesions in childhood ALL. Material and Methods: We included a national cohort of ALL patients diagnosed with symptomatic ON before 18 years of age and treated with BPs (N = 10; five males). Patients were followed both clinically and with serial MRIs. ON lesions were graded according to the Niinimaki classification. Results: The 10 patients had a total of 55 ON lesions. The median age was 13.3 years at ALL diagnosis and 14.8 years at ON diagnosis. Four patients had received HSCT before the ON diagnosis. BPs used were pamidronate (N = 7), alendronate (N = 2) and ibandronate (N = 1). The duration of BP treatment varied between 4 months and 4 years. In 4/10 patients, BP treatment was given during the chemotherapy. BPs were well-tolerated, with no severe complications or changes in kidney function. At the end of follow up 13/55 (24%) ON lesions were completely healed both clinically and radiographically; all these lesions were originally graded 3 or less. In contrast, ON lesions originally classified as grade 5 (joint destruction; N = 4) remained at grade 5. All grade 5 hip joint lesions needed surgical treatment. During BP treatment, the pain was relieved in 7/10 patients. At the end of follow-up, none of the patients reported severe or frequent pain. Conclusion: BP treatment was safe and seemed effective in relieving ON-induced pain in childhood ALL. After articular collapse (grade 5) lesions did not improve with BP treatment. Randomized controlled studies are needed to further elucidate the role of BPs in childhood ALL-associated ON.Peer reviewe