Making the most of time in quantum metrology: concurrent state preparation and sensing

A quantum metrology protocol for parameter estimation is typically comprised of three stages: probe state preparation, sensing and then readout, where the time required for the first and last stages is usually neglected. In the present work we consider non-negligible state preparation and readout times, and the tradeoffs in sensitivity that come when a limited time resource T must be divided between the three stages. To investigate this, we focus on the problem of magnetic field sensing with spins in one-axis twisted or two-axis twisted states. We find that (accounting for the time necessary to prepare a twisted state) no advantage is gained unless the time T is sufficiently long or the twisting sufficiently strong. However, we also find that the limited time resource is used more effectively if we allow the twisting and the magnetic field to be applied concurrently, which possibly represents a more realistic sensing scenario. We extend this result into an optical setting by utilizing the exact correspondence between a spin system and a bosonic field mode as given by the Holstein-Primakoff transformation

Comorbidade entre Transtorno Obsessivo Compulsivo e Transtorno de Ansiedade Generalizada: um estudo de caso

Introdução: O Transtorno Obsessivo-Compulsivo (TOC) caracteriza-se pela presença de obsessões e compulsões, enquanto o Transtorno de Ansiedade Generalizada (TAG) é caracterizado pela presença de preocupações excessivas e ansiedade elevada. Estudos apontam comorbidade frequente entre TOC e de TAG, pelo fato de ambas apresentarem sintomas de ansiedade, provenientes das obsessões e preocupações, além de afetarem a qualidade de vida dos acometidos por essas psicopatologias. Objetivo: Descrever, por meio de um relato de caso clínico, a comorbidade entre o TOC e o TAG. Metodologia: Estudo de caso clínico de um paciente de ambulatório de transtornos ansiosos. Foi realizada entrevista semiestruturada para avaliar a presença de obsessões e preocupações e obter o diagnóstico de transtornos mentais. Também foram aplicados inventários de ansiedade, qualidade de vida, habilidades sociais e sintomas obsessivo-compulsivos. Resultados: O paciente apresenta sofrimento significativo associado às obsessões e preocupações. Os inventários também apontaram baixa qualidade de vida, ansiedade e sintomas obsessivo-compulsivos com intensidade de moderadosa graves, baixas habilidades sociais. Conclusão: A comorbidade entre esses transtornos estão associadas ao pior prognóstico e ao aumento da ansiedade proveniente das obsessões e preocupações. Discutiram-se as características clínicas desses transtornos

Quantum phase space picture of Bose-Einstein Condensates in a double well: Proposals for creating macroscopic quantum superposition states and a study of quantum chaos

We present a quantum phase space model of Bose-Einstein condensate (BEC) in a double well potential. In a two-mode Fock-state analysis we examine the eigenvectors and eigenvalues and find that the energy correlation diagram indicates a transition from a delocalized to a fragmented regime. Phase space information is extracted from the stationary quantum states using the Husimi distribution function. It is shown that the quantum states are localized on the known classical phase space orbits of a nonrigid physical pendulum, and thus the novel phase space characteristics of a nonrigid physical pendulum such as the $\pi$ motions are seen to be a property of the exact quantum states. Low lying states are harmonic oscillator like libration states while the higher lying states are Schr\"odinger cat-like superpositions of two pendulum rotor states. To study the dynamics in phase space, a comparison is made between a displaced quantum wavepacket and the trajectories of a swarm of points in classical phase space. For a driven double well, it is shown that the classical chaotic dynamics is manifest in the dynamics of the quantum states pictured using the Husimi distribution. Phase space analogy also suggests that a $\pi$ phase displaced wavepacket put on the unstable fixed point on a separatrix will bifurcate to create a superposition of two pendulum rotor states - a Schr\"odinger cat state (number entangled state) for BEC. It is shown that the choice of initial barrier height and ramping, following a $\pi$ phase imprinting on the condensate, can be used to generate controlled entangled number states with tunable extremity and sharpness.Comment: revised version, 13 pages, 13 figure

Phase engineering of controlled entangled number states in a single component Bose-Einstein condensate in a double well

We propose a model for the creation of entangled number states (Schr\"odinger cat states) of a Bose-Einstein condensate in a double well through simple phase engineering. We show that a $\pi$-phase imprinted condensate in a double-well evolves, with a simultaneous change of barrier height, to number states with well defined and controlled entanglement. The cat state generation is understood in terms of the underlying classical phase space dynamics of a $\pi$-phase displaced coherent state put at the hyperbolic fixed point of the separatrix of a physical pendulum. The extremity and sharpness of the final cat state is determined by the initial barrier height and the rate at which it is ramped during the evolution.Comment: 11 pages, 5 figures, Submitted to J. Phys. B (letter to the editor

AEDGE: Atomic Experiment for Dark Matter and Gravity Exploration in Space

Abstract: We propose in this White Paper a concept for a space experiment using cold atoms to search for ultra-light dark matter, and to detect gravitational waves in the frequency range between the most sensitive ranges of LISA and the terrestrial LIGO/Virgo/KAGRA/INDIGO experiments. This interdisciplinary experiment, called Atomic Experiment for Dark Matter and Gravity Exploration (AEDGE), will also complement other planned searches for dark matter, and exploit synergies with other gravitational wave detectors. We give examples of the extended range of sensitivity to ultra-light dark matter offered by AEDGE, and how its gravitational-wave measurements could explore the assembly of super-massive black holes, first-order phase transitions in the early universe and cosmic strings. AEDGE will be based upon technologies now being developed for terrestrial experiments using cold atoms, and will benefit from the space experience obtained with, e.g., LISA and cold atom experiments in microgravity. KCL-PH-TH/2019-65, CERN-TH-2019-12

Psicoterapia versus farmacoterapia no tratamento do transtorno obsessivo-compulsivo: uma revisão sistemática

Introdução: O Transtorno Obsessivo-Compulsivo (TOC) é caracterizado pela presença de obsessões e compulsões e causam prejuízo funcional e sofrimento significativo ao sujeito. Os tratamentos de primeira escolha para o TOC são os inibidores seletivos da recaptação da serotonina  (ISRS) e a psicoterapia (comportamental ou cognitivo-comportamental), utilizando, principalmente, Exposição e Prevenção de Respostas (EPR).  Objetivo: Revisar sistematicamente os artigos publicados nos últimos 15 anos que comparam a eficácia da psicoterapia versus a farmacoterapia no tratamento do TOC. Metodologia: Os artigos foram buscados nos bancos de dados PubMed/Medline e Web of Science,  com os termos obsessive compulsive disorder, pharmacotherapy e cognitive behavior therapy.. Foram selecionados ensaios clínicos que comparassem ambas as terapias no período de janeiro de 1997 a agosto de 2012. Resultados: Foram incluídos 13 artigos. Seis artigos apontaram que a combinação de ambas as terapias é melhor que a monoterapia, para a redução dos sintomas do TOC (n=6); outros afirmaram que o tratamento combinado não difere da monoterapia (n=4). Alguns estudos apontaram que a psicoterapia é mais eficaz que o fármaco (n=3), enquanto outros indicaram que não há diferenças significativas entre as intervenções (n=4). Conclusão: As técnicas psicoterapêuticas mostram-se eficientes por si só, no tratamento do TOC. A técnica mais empregada é a EPR. A combinação entre fármaco e psicoterapia parece ser o tratamento ideal para o sujeito com TOC, pois juntas modificam mais os sintomas, o que parece ter maior duração do que apenas a utilização do fármaco.   Abstract Introduction: Obsessive-Compulsive Disorder (OCD) is characterized by the presence of obsessions and compulsions, and cause significant distress and functional impairment to the subject. The treatments of first choice for OCD is the selective serotonin reuptake inhibitors and psychotherapy (behavioral or cognitive-behavioral), using mainly Exposure with Response Prevention (ERP). Objective: To systematically review the articles published in the last 15 years comparing the effectiveness of psychotherapy versus pharmacotherapy in the treatment of OCD. Methods: Articles were searched on the databases PubMed / Medline and Web of Science, with terms obsessive compulsive disorder,  pharmacotherapy and cognitive behavior therapy. Were included trials that compared the two therapies in the period of January of 1997 to august of 2012. Results: Were included 13 articles. Six studies showed that the combination of both therapies is better than the monotherapy in the reduction of OC symptoms (n = 6), other, said combined treatment does not differ from monotherapy (n = 4). Some studies have indicated that psychotherapy is more effective than the drug (n = 3), while others indicated that no significant differences between the interventions (n = 4). Conclusion: Psychotherapeutic techniques prove to be effective alone for the treatment of OCD. The most common technique is the ERP. The combination of psychotherapy and drug therapy appears to be ideal for the subject with OCD, because together modify more the symptoms, which seems to be more duration than just the of drug use

Psicoterapia versus farmacoterapia no tratamento do transtorno obsessivo-compulsivo: uma revisão sistemática

Introdução: O Transtorno Obsessivo-Compulsivo (TOC) é caracterizado pela presença de obsessões e compulsões e causam prejuízo funcional e sofrimento significativo ao sujeito. Os tratamentos de primeira escolha para o TOC são os inibidores seletivos da recaptação da serotonina  (ISRS) e a psicoterapia (comportamental ou cognitivo-comportamental), utilizando, principalmente, Exposição e Prevenção de Respostas (EPR).  Objetivo: Revisar sistematicamente os artigos publicados nos últimos 15 anos que comparam a eficácia da psicoterapia versus a farmacoterapia no tratamento do TOC. Metodologia: Os artigos foram buscados nos bancos de dados PubMed/Medline e Web of Science,  com os termos obsessive compulsive disorder, pharmacotherapy e cognitive behavior therapy.. Foram selecionados ensaios clínicos que comparassem ambas as terapias no período de janeiro de 1997 a agosto de 2012. Resultados: Foram incluídos 13 artigos. Seis artigos apontaram que a combinação de ambas as terapias é melhor que a monoterapia, para a redução dos sintomas do TOC (n=6); outros afirmaram que o tratamento combinado não difere da monoterapia (n=4). Alguns estudos apontaram que a psicoterapia é mais eficaz que o fármaco (n=3), enquanto outros indicaram que não há diferenças significativas entre as intervenções (n=4). Conclusão: As técnicas psicoterapêuticas mostram-se eficientes por si só, no tratamento do TOC. A técnica mais empregada é a EPR. A combinação entre fármaco e psicoterapia parece ser o tratamento ideal para o sujeito com TOC, pois juntas modificam mais os sintomas, o que parece ter maior duração do que apenas a utilização do fármaco.   Abstract Introduction: Obsessive-Compulsive Disorder (OCD) is characterized by the presence of obsessions and compulsions, and cause significant distress and functional impairment to the subject. The treatments of first choice for OCD is the selective serotonin reuptake inhibitors and psychotherapy (behavioral or cognitive-behavioral), using mainly Exposure with Response Prevention (ERP). Objective: To systematically review the articles published in the last 15 years comparing the effectiveness of psychotherapy versus pharmacotherapy in the treatment of OCD. Methods: Articles were searched on the databases PubMed / Medline and Web of Science, with terms obsessive compulsive disorder,  pharmacotherapy and cognitive behavior therapy. Were included trials that compared the two therapies in the period of January of 1997 to august of 2012. Results: Were included 13 articles. Six studies showed that the combination of both therapies is better than the monotherapy in the reduction of OC symptoms (n = 6), other, said combined treatment does not differ from monotherapy (n = 4). Some studies have indicated that psychotherapy is more effective than the drug (n = 3), while others indicated that no significant differences between the interventions (n = 4). Conclusion: Psychotherapeutic techniques prove to be effective alone for the treatment of OCD. The most common technique is the ERP. The combination of psychotherapy and drug therapy appears to be ideal for the subject with OCD, because together modify more the symptoms, which seems to be more duration than just the of drug use

Morbidade psiquiátrica entre adolescentes em conflito com a lei Psychiatric morbidity among adolescents in conflict with the law

OBJETIVO: Descrever o perfil psiquiátrico, destacando os transtornos em co-morbidade entre os adolescentes em conflito com a lei da Casa de Acolhimento ao Menor (CAM), Salvador-BA, em 2003. MÉTODOS: Estudo de corte transversal, de caráter censitário, em população de 290 jovens cumprindo medidas de privação de liberdade. Utilizaram-se questionário para identificar dados demográficos, sinais e sintomas psicopatológicos e entrevista semi-estruturada para o exame dos adolescentes. RESULTADOS: Perfil sociodemográfico: 89,3% sexo masculino; 63,9% entre 15 e 18 anos incompletos; 95,1% com ensino fundamental incompleto ou analfabeto; 67,6% com renda familiar menor que um salário mínimo e 54% naturais da capital do estado da Bahia. Dos 290 indivíduos, 24,8% não apresentaram transtornos mentais e 75,2% preencheram critérios para um ou mais transtornos psiquiátricos de acordo com a décima revisão da Classificação Internacional de Doenças (CID-10). Entre os 218 jovens portadores de patologia, 47,7% apresentaram transtornos em co-morbidade.Aassociação de patologia mais prevalente foi entre transtornos de conduta e transtornos por uso nocivo de substância psicoativa (13,4%). Transtornos hipercinéticos só foram freqüentes quando associados a outras condições (10,7%). O uso nocivo de substância psicoativa foi identificado em combinação com os diversos quadros psiquiátricos. CONCLUSÃO: Observou-se alta taxa de co-morbidade psiquiátrica, sugerindo a necessidade de estratégias terapêuticas específicas entre jovens portadores de transtornos mentais envolvidos com a justiça.<br>OBJECTIVE: To describe the psychiatric profile, with emphasis on psychiatric comorbidities, of adolescents in conflict with the law interned on Casa de Acolhimento ao Menor (CAM), Salvador, Bahia, 2003. METHODS: This is a cross-sectional census study that enrolled a population of 290 adolescents kept on a deprivation of liberty regimen. Aquestionnaire was used to collect demographic and psychosocial data as well as psychopathologic signs and symptoms, and a semi-structured interview was carried out on the examination of the enrolled adolescents. RESULTS: Social-demographic profile: male (89.3%); between 15 and 18 years (63.9%), analphabets or had not completed the basic school years (95.1%); monthly family income below one minimum salary (67.6%). Among the 290 enrolled adolescents, 24.8% had no mental disturbance, while 75.2% fulfilled criteria to one or more psychiatric disorders according to ICD-10. Out of 218 adolescents who had at least one diagnosis, 47.7% had comorbidity disorders. The commonest association of conditions was between behavioral disorders and the noxious use of psychoactive drugs (13.4%). Hyperkinetic disorders are only frequent when associated with other conditions (10.7%). The noxious use of psychoactive drugs was also shown to be present, being noted in association with diverse psychiatric conditions. CONCLUSION: Ahigh rate of psychiatric comorbidity was found, suggesting the need for specific therapeutic approaches to aid adolescents with psychiatric conditions and in conflict with the law