A5047793714- Quantum Computing Algorithms and Architecture
- Quantum Information and Cryptography
- Advancements in Semiconductor Devices and Circuit Design
- Quantum many-body systems
- Parallel Computing and Optimization Techniques
- Quantum-Dot Cellular Automata
- graph theory and CDMA systems
- Coding theory and cryptography
- Quantum and electron transport phenomena
- Semiconductor materials and devices
- Matrix Theory and Algorithms
- Advanced Condensed Matter Physics
Indian Institute of Technology Madras
2018-2022
With the intense interest in small, noisy quantum computing devices comes push for larger, more accurate -- and hence useful computers. While fully fault-tolerant computers are, principle, capable of achieving arbitrarily calculations using subjected to general noise, they require immense resources far beyond our current reach. An intermediate step would be construct limited accuracy enhanced by lower-level, lower-cost, noise-removal techniques. This is motivation work, which looks into...
Rapid progress in developing near- and long-term quantum algorithms for chemistry has provided us with an impetus to move beyond traditional approaches explore new ways apply computing electronic structure calculations. In this work, we identify the connection between many-body theory a linear solver, implement Harrow-Hassidim-Lloyd (HHL) algorithm make precise predictions of correlation energies light molecular systems via (nonunitary) linearized coupled cluster theory, where term ``light...
We present a simple and fast numerical procedure to search for good quantum codes storing logical qubits in the presence of independent per-qubit noise. In key departure from past work, we use worst-case fidelity as figure merit quantifying code performance, much better indicator quality than, say, entanglement fidelity. Yet our algorithm does not suffer inefficiencies usually associated with Specifically, using near-optimal recovery map, are able reduce triple optimization needed single...
We examine the role of quantum error correction (QEC) in achieving pretty good state transfer over a class $1$-d spin Hamiltonians. Recasting problem as one information transmission an underlying channel, we identify adaptive QEC protocol that achieves transfer. Using recovery and approximate code, obtain explicit analytical numerical results for fidelity ideal disordered Heisenberg chains. In case chain, study distribution transition amplitude, which turn quantifies stochastic noise...
Although the Harrow-Hassidim-Lloyd (HHL) algorithm offers an exponential speedup in system size for treating linear equations of form $A\vec{x}=\vec{b}$ on quantum computers when compared to their traditional counterparts, it faces a challenge related condition number ($\mathcal{\kappa}$) scaling $A$ matrix. In this work, we address issue by introducing post-selection-improved HHL (Psi-HHL) approach that involves simple yet effective modification extract feature $|x\rangle$, and which leads...
Rapid progress in developing near- and long-term quantum algorithms for chemistry has provided us with an impetus to move beyond traditional approaches explore new ways apply computing electronic structure calculations. In this work, we identify the connection between many-body theory a linear solver, implement Harrow-Hassidim-Lloyd (HHL) algorithm make precise predictions of correlation energies light molecular systems via (non-unitary) linearised coupled cluster theory. We alter HHL...
A major obstacle towards realizing a practical quantum computer is the noise that arises due to system-environment interactions. While it very well known error correction (QEC) provides way protect against errors arise affecting system, perfect code requires atleast five physical qubits observe noticeable improvement over no-QEC scenario. However, in cases where structure system already known, might be more useful consider codes are adapted specific models. It literature such resource...
The quantum computing devices of today have tens to hundreds qubits that are highly susceptible noise due unwanted interactions with their environment. theory error correction provides a scheme by which the effects such on states can be mitigated, paving way for realising robust, scalable computers. In this article we survey current landscape correcting (QEC) codes, focusing recent theoretical advances in domain noise-adapted QEC, and highlighting some key open questions. We also discuss...