**1. Sabarmati Young Researchers Seminar: 9th Jan 2020: Generating steady state coherence a solid state qubit using quantum noise from phonons by Dr. Archak Purkayastha, a post-doctoral fellow in the group of John Goold at Trinity College, Dublin**

Title: **Generating steady state coherence a solid state qubit using quantum noise from phonons.**

Speaker: **Dr. Archak Purkayastha, Post Doctoral Fellow at Trinity College, Dubin.**

**Coordinates: 09 Jan 2020, 7/210**

**Abstract:** Much of quantum technology depends on generation and control of coherence in a qubit. In particular, coherence in the energy eigenbasis of a system has been recognized as a resource. However, coherence in energy eigenbasis is usually fragile. Interaction of the system with its surrounding environment provides noise in the qubit parameters, which in turn is thought to lead to decoherence, i.e, loss of coherence in the energy eigenbasis. In this talk, I will show that while this is true for classical noise in qubit parameters, quantum noise in qubit parameters actually generates coherence in the energy eigenbasis of the qubit under generic conditions. This coherence occurs in the steady state and is therefore robust. This is particularly interesting in the context of a solid state double-quantum-dot (DQD) charge qubit where quantum noise from phonons in the substrate is the leading source of noise. Moreover, the DQD charge qubit is widely tunable, and by controlling its parameters, regimes of high purity along with coherence in energy eigenbasis can be found. The coherence is robust to presence of fermionic leads at equilbrium, and can be used to displace a cavity mode.

**Bio:** Archak graduated with Bachelors degree in Physics from Jadavpur University, Kolkata, in 2011, followed by a Masters Degree in Physics from Indian Institute of Technology, Kanpur, in 2013. Then he did his Ph.D at the International Centre for Theoretical Sciences, Tata Institute for Fundamental Research (ICTS-TIFR), Bangalore, under the supervision of Prof. Abhishek Dhar. He defended his PhD in September, 2018. He stayed at ICTS-TIFR till December, 2018 as a visiting-fellow. From Feb 1, 2019, he has joined the QuSys team of John Goold at Trinity College, Dublin for his post-doctoral research. During his PhD, he has developed expertise in the formalism for investigating transport phenomena in open quantum systems. In Dublin he is exploring thermodynamics of open quantum systems, and applications of open quantum systems in building, for example, quantum engines and sensors.

**2. Seminar Series on Indian scientists**: **1st edition on October 5, 2019**

We are glad to announce the first edition of what we hope will be a biannual event: a seminar series on Indian scientists.

In the late 19th century and the first half of the 20th century, there was a great renaissance of modern scientific thinking in India. The father figures of modern Indian Science from this era contributed significantly to contemporary scientific advances. At the same time, they motivated and led the national movement to create scientific institutions in India. This Seminar Series on Indian Scientists aims to honour the contributions of these often half-forgotten pioneers.

Each seminar in the series will be of one day, with a mix of speakers from outside and within IITGn. In this first edition, on Saturday 5th October, we will have four lectures on the lives and works of Satyendranath Bose, Meghnad Saha, G.N. Ramachandran, and Prafulla Chandra Roy. The programme’s schedule and abstracts can be downloaded here.

Students & Faculty members from all institutions are invited. For non-IIT Gandhinagar participants, registration is free but mandatory; to register, please fill this Google form.

**3. Sabarmati Young Researchers Seminar: 8th & 9th August 2019: Anomaly and Index Theorem by Dr. Arnab Rudra, ICTP, Italy**.

Title: **Anomaly and Index Theorem.**

Speaker: **Dr. Arnab Rudra, ICTP, Italy.**

Lecture 1: **8th August, Block 6/203, 4 - 5:15 PM**

Lecture 2: **9th August, Block 6/203. 4 - 5:15 PM**

Abstract: Quantum violation of a classical symmetry is known as an anomaly. We discuss when and how an anomaly appears in the quantum theory. The presence of anomaly is related to the presence of zero energy states and Index theorems count the number of such zero energy states. We will present an introduction to the index theorem in general. In the end, we will discuss the Atiyah-Patodi-Singer (APS) Index theorem and we will present a physicist's derivation of the same.

**Brief Bio of the Speaker:**

Dr. Arnab Rudra completed his Part III, Mathematical Tripos and Ph.D. from the Department of Applied Mathematics and Theoretical Physics, University of Cambridge, United Kingdom. After finishing his first Postdoc at University of California, Davis, USA, he is currently working as a Postdoctoral fellow at the Abdus Salam International Center for Theoretical Physics (ICTP), Italy. His research interests are String theory, Quantum Field theory, and Mathematical Physics.

© 2020 All Rights Reserved