Detecting subsystem symmetry protected topological order via entanglement entropy

Subsystem symmetry protected topological (SSPT) order is a type of quantum order that is protected by symmetries acting on lower-dimensional subsystems of the entire system. In this paper, we show how SSPT order can be characterized and detected by a constant correction to the entanglement area law, similar to the topological entanglement entropy. Focusing on the paradigmatic two-dimensional cluster phase as an example, we use tensor network methods to give an analytic argument that almost all states in the phase exhibit the same correction to the area law, such that this correction may be used to reliably detect the SSPT order of the cluster phase. Based on this idea, we formulate a numerical method that uses tensor networks to extract this correction from ground-state wave functions. We use this method to study the fate of the SSPT order of the cluster state under various external fields and interactions, and find that the correction persists unless a phase transition is crossed, or the subsystem symmetry is explicitly broken. Surprisingly, these results uncover that the SSPT order of the cluster state persists beyond the cluster phase, thanks to a new type of subsystem time-reversal symmetry. Finally, we discuss the correction to the area law found in three-dimensional cluster states on different lattices, indicating rich behavior for general subsystem symmetriesComment: 17 pages. v2: Published version, minor changes throughou

Die Departement Praktiese Teologie (Afd A): Die ‘De Wet-era’ en daarna

The Department of Practical Theology (Sec A): The ‘De Wet era’ and subsequent yearsThe Department of Practical Theology (Sec A) at the University of Pretoria was established in 1968 when Professor J I de Wet was appointed head of the Department. He held this position until his death in 1983. He can thus be depicted as the ‘father’ of Practical Theology within the Faculty. This paper is an attempt to identifyhis viewpoints and to trace his influence in the academic and ecclesiastic spheres. The results show that he can be described as a practical theologian who stood for the preservation of the theological character of this discipline, based on biblical principals. He rejected the ‘gesellschaft’ as theoretical basis for Practical Theology. Trends since his death in 1983 will also be identified

Die akkommodering en bestuur van diversiteit in gemeenteverband

The accommodation and management of diversity at congregational levelDiversity is becomming a prominent phenomenon of our society within a postmodern context. Many clergy and church members believe it threatens the peace and stability of churches and local congregations. Seemingly, diversity contributes to the escalation of conflict and the stress levels church leaders are experiencing. This article attempts to analize and describe the phenomenon of diversity from the angles of postmodernity, personality preferences and systems thinking. The research is based upon the hypothesis that diversity does not necessarily threaten the unity of local congregations. The manifestation of unity within diversity is only possible if leaders are sensitized to manage the challenges of pluriformity

Karl Barth as a homilist

Any tribute to Karl Barth as the most important theologian of the 20th century must show an awareness of the many facets of his work. He will long be remembered for his monumental contribution to church dogmatics. The inspiration for his dogmatics was his dilemma in preaching the Word of God. Preaching and proclaiming the Word of God were his main interests. This article attempts to analyse his homiletic stance, not only as an academic theory, but in relation to his own sermons. Finally, the importance of Barth’s theology for preaching in a postmodern society is outlined

Poging tot ’n herdefínisie van die prediking binne die raamwerk van die Reformatiese teologie

An attempt to redefine preaching in terms of Reformational theologyIn the field of biblical studies and hermeneutics, modern research, in many aspects results in questioning the authority of the Bible as the Word of God. Theconsequences of these results often undermine preaching as the Word of God. Within the theology of the reformation , preaching is based upon sound exegetical study and expository of the biblical text. Hence scientific exegetical research brings the authorityof preaching to a crisis. This paper is an attempt to redefine preaching in order to incorporate the results of modem research, as well as to conserve the fundamental concept of preaching as the Word of God

'n Praktíes-teologiese evaluering van moontlike bedieningstrukture in die Nederduitsch Hervormde Kerk toegespits op die rol van die predikant

A practical theological evaluation of potential structures oi ministry within the Nederduitsch Hervormde Kerk, focused on the role of the ministerDie modern society in which the church has to fulfill its ministry, differs in many aspects from the traditional society. The question arises whether the old pattern of ministry is still sufficient to accommodate new trends. This paper is an attempt to identify and establish alternative structures. This is done by means of investigating and exploring scriptural perspectives on church ministry. Certain alternative models are weighed against biblical findings and modem concepts. Finally, a revised pattern ofministry is proposed

Acute confusion and ataxia in the emergency department with an unexpected underlying diagnosis

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Abnormal swallowing habits

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Die benutting van vraelyste met die oog op meer effektiewe toerusting tydens huweliksvoorbereiding

The utilization of questionnaires with the intent to make marriage preparation more effectiveThis study aims to promote the idea that questionnaires used as part of marriage preparation, could be a valuable tool. The article also attempts to identify some themes that should form part of the discussion between the pastor and a couple to prepare them for their marriage. Furthermore, the aim is to assist pastors, especially those in the Nederduitsch Hervormde Kerk van Afrika, utilizing questionnaires during marriage preparation

Oral medicine case book 53: radiation - induced xerostomia

A 76-year old male presented at the Oral Medicine Clinic, complaining of a persistent feeling of a dry mouth, subsequent to having undergone surgery, chemotherapy and radiation therapy for nasopharyngeal carcinoma, 18 months previously. Other than the cancer, he had no systemic problems of note and was otherwise in good physical health. Upon further questioning, the patient reported that the dry mouth condition was affecting his quality of life and that he was losing weight due to difficulty in eating. He further emphasised that his mouth felt dry within five minutes of rinsing his mouth with the palliative agents suggested by his dentist and oncologist. The regimen he followed to relieve his symptoms included glycerine BP oil, Candacide© (a nystatin containing product), Biotene© mouth spray and mouthrinse (these products contain lactoperoxidase, glucose oxidase, lysozyme and lactoferrin), Orbit© sugar free gum and an increased frequency of water intake.Department of HE and Training approved lis