Principal Investigator: Prof. Subhadeep De

Co-PI: Prof. Subhasis Panja

The underlined sophisticated engineering goals for achieving satellite based free space optical quantum communication or optical fibre based quantum communication are: (i) ultra‐precise atomic clock, (ii) low noise weak optical signal detector, (iii) photon source, (iv) low loss optical elements, (v) wave guides, (vi) quantum repeaters, (vii) fast feedforward and (viii) and many more quantum enhanced technologies. In particular, the atomic clocks plays as backbone for the accurate “time stamping” on the signal packets and also for establishing “time synchronization” among the devices that are placed at different locations. The signals, i.e. wave packets, at the receiving end are very weak (typically < 0.1 photon per pulse). However, they are detected at a high confidence level, even in the presence of a strong background using correlation measurement techniques. The correlation measurement relies on chopping of the transmitted and received signals in smaller time window and comparing them relative to each other. For that purpose accurate “time synchronization” between sender and receiver is also essential besides the “time stamping”. This demands more accurate timing system than that is required for classical communication such as GPS based microwave communication. As for example the present satellite based GPS communication uses timing systems with approximately 20 ns accuracy (GPS time is accurate to ~ 20 ns). However, the quantum communication demands ps accuracy. Optical atomic clocks, which are so accurate that they lose few seconds over the age of the universe (accuracy is approximately 1 part in 1018), are the backbone for the purpose of quantum communication.

Principal Investigator: Prof. Ajay Wasan

Co-PIs: Prof. Rajesh Srivastava

We propose to trap few atoms in dipole trap for quantum gate operation. We plan to set up experiments to capture few rubidium atoms from the magneto‐optic trap (MOT) into far off resonance traps (FORT). We will develop the technique to tune the interaction between large Rydberg atoms as it will allow us to implement two qubit quantum gate to multiple quantum gates operation. After this 4 to 10 atoms will be trapped in the FORT to make parallelly many CNOT gates. The specific goal of the project is to trap few atoms in a dipole trap to make CNOT gates to construct complex logic gates. These gates operations are basic block of Quantum Computer.

Principal Investigator: Prof. Kanhaiya Pandey

Co-PIs: Prof. Tapan Mishra

We are planning to address the scalable quantum computing in this proposal using the Yb atoms in the optical lattices. Unlike the previous experimental demonstrations limited to few qubits, this proposal involves the quantum computation having large no of the qubits. The neutral atoms in an optical lattice is promising system due to it’s scalability, as typically 104‐105 atoms can be loaded into an optical lattice, and each atom confined in the individual site of the optical lattice is regarded as a qubit

Principal Investigator: Prof. Prabha Mandayam

Co-PI: Prof. Pradeep Sarvepalli

Building a scalable quantum computer requires quantum error correcting codes.Our goal is to develop efficient, high‐performance QEC protocols based on novel, emerging techniques. We shall pursue the following directions of research in our proposal:

1. Active error‐correction schemes, specifically, holographic codes

2. (Partially) Self‐error correcting schemes, specifically, fractal codes

3. Adaptive or Approximate QEC, with connections to quantum secret sharing

4. Applications of QEC to specific physical systems and quantum tasks

Principal Investigator: Prof. Anu Venugopalan

The proposal is two‐fold:

1. We will seek to explore the relationship between various entanglement quantifiers and quantum correlations in typical experimentally meaningful scenarios. In particular, we will look at their time evolution to get significant insights which can be applied to real experimental situations involving the production and manipulation of qubits for quantum information applications. A study is proposed to be undertaken of the time evolution of different quantum systems in various experimentally realizable physical systems such as neutral atoms in optical lattices, double quantum dots (quantum molecules), quantum magnets and superconducting qubit devices etc. with interactions leading to entanglements. The objectives are to explore intrinsic connections between the various quantifiers of quantum correlations and entanglement as a function of time. The aim is to get both a better understanding of these subtle concepts as well as insights into possible applications in the fields of quantum communication and cryptography.

2. It is well known that the quantum mechanical interaction between two particles, designated as ‘system’ and the ‘apparatus’, describes a quantum measurement scenario and creates an entangled state containing quantum correlations which are “non classical”. The problem of quantum measurement and the appearance of classical like correlations remains a topic of much debate. We will explore the connection between entanglement generation in a quantum measurement and its evolution to give classical correlations in various measurement‐like scenarios. Quantum measurement is a significant part of ‘read out’ in quantum computing applications as well as in quantum communication protocols.

Principal Investigator: Prof. Arul Lakshminarayan

Co-PI: Prof. Vaibhav Madhok

The entanglement of states is well‐studied in the literature, the entangling power of operators – the ability of unitary operators to generate entanglement – is not fully understood. To this end, we would like to study the entangling power of general non‐local quantum operations, especially the effect of interspersing these with local operations. It is appreciated that local operations can significantly enhance entangling power of nonlocal ones if they are used together.

Principal Investigator: Prof. Radhika Vathsan

Mathematical aspects of quantum correlations for open systems and mixed states are a fundamental problem in quantum systems that are utilized in quantum information processing. Much of current work involves algebraic and entropic study of quantum entanglement. In this project we wish to study dynamic aspects quantum correlations from a geometric perspective, starting from the notion of information geometry and correlations between probability distributions. We wish especially to study how these correlations change or evolve during quantum dynamics, and in the measurement process. We also wish to establish a connection with the classical limit, which becomes relevant in the quantum‐classical transition natural to the measurement process. This study will further aid the process of recognizing decoherence mechanisms and their control, in particular applications to information encoding and decoding.

Principal Investigator: Prof. Umakant D. Rapol

Co-PI: Prof. MS Santhanam

We propose to develop novel experimental platform for achieving strong coupling of ultracold Strontium (Sr) atoms with plasmon‐polariton modes in conducting (Silver, Gold) tapered nanowires and nanostructures. This platform will be the basis for quantum networking of discrete quantum nodes connected via photonic quantum channels.

Principal Investigator: Prof. Ujjwal Sen

Co-PI: Prof. Arun Kumar Pati

The foci of the research in the proposed project will be on (a) theoretical analysis of noise in realistic quantum devices for quantum computing and other technologies, and (b) theoretical characterization of entanglement in realistic quantum devices. The specific quantum systems to be studied will include ion traps, optical lattices, solid state, and magnetic resonance systems.