Quantum computing has gained significant attention due to its potential to solve a set of computational problems faster than classical algorithms. A fully functional, scalable quantum computer could revolutionize fields such as scientific discovery, materials research, and chemistry. My research in quantum computing focuses on two key questions: How can we develop a reliable quantum computer whose output we can trust? and How can we utilize such a quantum computer for practical applications? To address these, my research is organized into four sub-directions:
Quantum Device Certification: Quantum computation is expected to outperform classical computation by an exponential margin. This raises a tough question: how can we be sure that these quantum devices are working correctly, or even that they are genuinely quantum? There’s a risk that a server might be using a classical device while falsely claiming to perform quantum computations. Addressing these concerns is essential for the continued trust and integration of quantum technologies into critical applications.
Quantum Error Correction: A major obstacle in building quantum computers is the fragility of quantum information, which is easily corrupted by noise. My research in this area focuses on quantum error correction as a way to protect quantum information. I explore approaches to make quantum error correction a practical reality.
Near-Term Quantum Computing: Can quantum computing devices outperform classical ones in the near future? This question drives my research into near-term quantum computing. I use both rigorous tools from quantum complexity theory as well as heuristic approaches to investigate the possibility of quantum advantage in the near future.
Computational Quantum Cryptography: In a future where quantum computers are fully operational, securing information will become crucial. My research in computational quantum cryptography focuses on designing cryptosystems with minimal assumptions, ensuring security even in a quantum-enabled world. Moreover, I am interested in the applications of these computational quantum cryptographic techniques in the three aforementioned sub-directions.
Academic metrics
Total papers: 50 (Including publications in top-tier journals such as PRL, PRX Quantum, npjQI and RMP; and conferences such as FOCS, QIP, TQC, AQIS and Beyond IID), Citations: 2789 (as of Feb 15, 2025); ORCID: 0000-0002-7776-6608.
(50) Approximate Dynamical Quantum Error-Correcting Codes, N Basak, A Tanggara, A Mohan, G Paul, K Bharti, arXiv:2502.09177.
(49) Contextuality of Quantum Error-Correcting Codes, D Khu, A Tanggara, K Bharti, arXiv:2502.02553.
(48) Pseudorandom quantum authentication, T Haug, N Bansal,WK Mok, DE Koh, K Bharti, arXiv:2501.00951.
(47) Quantum Policy Gradient in Reproducing Kernel Hilbert Space, DM Bossens, K Bharti, J Thompson, arXiv:2411.06650.
(46) Simple Construction of Qudit Floquet Codes on a Family of Lattices, A Tanggara, M Gu, K Bharti, arXiv:2410.02022.
(45) Local contextuality-based self-tests are sufficient for randomness expansion secure against quantum adversaries, J Singh, C Foreman, K Bharti, A Cabello,
arXiv:2409.20082.
(44) Pseudorandom density matrices, N Bansal,WK Mok, K Bharti, DE Koh, T Haug, arXiv:2407.11607.
(43) Multivariate Bicycle Codes, L Voss, SJ Xian,T Haug, K Bharti, arXiv:2406.19151.
(42) Communication with Quantum Catalysts, Y Li, J Xing, D Qu, L Xiao, Z Fan, Z Zheng, H Ma, P Xue, K Bharti, DE Koh, Y Xiao, arXiv:2406.14395.
(41) Teleportation with Embezzling Catalysts, J Xing, Y Li, D Qu, L Xiao, Z Fan, H Ma, P Xue, K Bharti, DE Koh, Y Xiao, arXiv:2406.14386.
(40) Strategic Code: A Unified Spatio-Temporal Framework for Quantum Error Correction, A Tanggara, M Gu, K Bharti, arXiv:2405.17567, Provided a unified
framework for all existing and future quantum error correcting codes; Accepted for a talk at Beyond IID and AQIS 24.
(39) Resource-Efficient Hybrid Quantum-Classical Simulation Algorithm, CH Chee, D Leykam, AM Mak, K Bharti, DG Angelakis, arXiv:2405.10528.
(38) A computational test of quantum contextuality, and even simpler proofs of quantumness, AS Arora, K Bharti, A Cojocoru, A Coladangelo, arXiv:2405.06787,
Solved a 60+ years old open problem in quantum foundations; Accepted at FOCS 2024.
(37) Classically Spoofing System Linear Cross Entropy Score Benchmarking, A Tanggara, M Gu, K Bharti, arXiv:2309.05735, Accepted for a contributed talk at
AQIS 2024.
(36) Estimation of Hamiltonian parameters from thermal states, LP Garcia-Pintos, K Bharti, J Bringewatt, H Dehghani, A Ehrenberg, NY Halpern, AV Gorshkov,
Physical Review Letters 133 (4), 040802.
(35) On the power of geometrically-local classical and quantum circuits, K Bharti, R Jain, arXiv:2310.01540.
(34) Fault-tolerant hyperbolic Floquet quantum error correcting codes, A Fahimniya, H Dehghani, K Bharti, S Mathew, AJ Kollár, AV Gorshkov, MJ Gullans, arXiv:2309.10033.
(33) Certifying sets of quantum observables with any full-rank state, ZP Xu, D Saha, K Bharti, A Cabello, Physical Review Letters 132 (14), 140201.
(32) A quantum tug of war between randomness and symmetries on homogeneous spaces, R Arvind, K Bharti, JY Khoo, DE Koh, JF Kong, arXiv:2309.05253,
Accepted for a contributed talk at QTML 2023.
(31) Inferring physical laws by artificial intelligence based causal models, J Singh, K Bharti, Arvind, arXiv:2309.04069.
(30) Pseudorandom unitaries are neither real nor sparse nor noise-robust, T Haug, K Bharti, DE Koh, arXiv:2306.11677, Accepted for a contributed talk at TQC 2024.
(29) Fundamental Limitations on Communication over a Quantum Network, J Xing, T Feng, Z Fan, H Ma, K Bharti, DE Koh, Y Xiao, arXiv:2306.04983.
(28) Certifying temporal correlations, H Shrotriya, LC Kwek, K Bharti, arXiv:2206.06092.
(27) NISQ algorithm for the matrix elements of a generic observable, R Erbanni, K Bharti, LC Kwek, D Poletti, SciPost Physics 15 (4), 180.
(26) Convex optimization for non-equilibrium steady states on a hybrid quantum processor, JW Zhong Lau*, KH Lim*, K Bharti, LC Kwek, Sai Vinjanampathy,
Phys. Rev. Lett. 130, 240601 (2023), Covered by CQT news highlight.
(25) Self-Testing of a Single Quantum System: Theory and Experiment, XM Hu*, Y Xie*, AS Arora*, MZ Ai*, K Bharti*, J Zhang, W Wu, PX Chen, JM Cui, BH
Liu, YF Huang, CF Li, GC Guo, J Roland, A Cabello, LC Kwek, npj Quantum Information 9 (1), 103.
(24) A Universal Uncertainty-Disturbance Relation, L. Sun, K Bharti, Y Mao, X Zhou, LC Kwek, J Fan and S Yu, arXiv:2202.07251.
(23) NISQ Algorithm for Semidefinite Programming, K Bharti, T Haug, V Vedral, LC Kwek, Physical Review A 105 (5), 052445.
(22) Graph-Theoretic Framework for Self-Testing in Bell Scenarios, K Bharti, M Ray, ZP Xu, M Hayashi, LC Kwek, A Cabello, PRX Quantum 3, 030344, Side result: proved a graph theory conjecture.
(21) Fast-Forwarding with NISQ Processors without Feedback Loop, KH Lim, T Haug, LC Kwek, K Bharti, Quantum Science and Technology, Volume 7, Number 1.
(20) NISQ Algorithm for Hamiltonian Simulation via Truncated Taylor Series, JW Zhong Lau, T Haug, LC Kwek, K Bharti, SciPost Phys. 12, 122 (2022).
(19) Capacity and Quantum Geometry of Parameterized Quantum Circuits, T Haug, K Bharti, MS Kim, PRX Quantum 2, 040309, Covered by CQT news highlight.
(18) Noisy Intermediate-Scale Quantum (NISQ) Algorithms, K Bharti*, AC Lierta*, TH Kyaw*, T Haug, SA Lea, A Anand, M Degroote, H Heimonen, JS Kottmann,
T Menke, WK Mok, S Sim, LC Kwek, AA Guzik, Rev. Mod. Phys. 94, 015004, (1000+ citations) Covered by CQT news highlight.
(17) Noisy intermediate scale quantum simulation of time dependent Hamiltonians, JW Zhong Lau, K Bharti, T Haug, LC Kwek, arXiv:2101.07677.
(16) Generalized Quantum Assisted Simulator, T Haug, K Bharti, Quantum Science and Technology 7 (4), 045019.
(15) Quantum Assisted Simulator, K Bharti, T Haug, Phys. Rev. A 104, 042418.
(14) Optimal Probes for Global Quantum Thermometry, WK Mok, K Bharti, LC Kwek, A Bayat, Communications Physics, 2021.
(13) Iterative Quantum Assisted Eigensolver, K Bharti, T Haug, Phys. Rev. A 104, L050401 .
(12) Quantum Assisted Eigensolver, K Bharti, arXiv:2009.11001.
(11) Graph-Theoretic Approach to Dimension Witnessing, M Ray, NG Boddu, K Bharti, LC Kwek, A Cabello, New Journal of Physics (2020).
(10) Robust Semi-Device-Independent Certification of all Pure Bipartite Maximally Entangled States via Quantum Steering, H. Shrotriya, K Bharti, LC
Kwek, Physical Review Research 3, 033093 (2021).
(9) Machine Learning meets Quantum Foundations: A Brief Survey, K Bharti, T Haug, V Vedral, LC Kwek, AVS Quantum Sci. 2, 034101 (2020), Featured Article.
(8) How to Teach AI to Play Bell Non-Local Games: Reinforcement Learning, K Bharti, T Haug, V Vedral, LC Kwek, arXiv:1912.10783.
(7) Towards Local Certification of Programmable Quantum Devices of Arbitrary High Dimensionality, K Bharti*, M Ray*, A Varvitsiotis, A Cabello, LC Kwek,
arXiv:1911.09448.
(6) Near-Term Quantum Algorithms for Linear Systems of Equations, HY Huang, K Bharti, P Rebentrost, New Journal of Physics, Volume 23, November 2021.
(5) Robust Self-Testing of Quantum Systems via Noncontextuality Inequalities, K Bharti, M Ray, A Varvitsiotis, NA Warsi, A Cabello, LC Kwek, Physical Review
Letters 122 (25), 250403, Covered by CQT news highlight.
(4) Non-Classical Correlations in n-Cycle Setting, K Bharti, M Ray, LC Kwek, Entropy 21 (2), 134.
(3) Uniqueness of All Fundamental Noncontextuality Inequalities, K Bharti*, AS Arora*, LC Kwek, J Roland, Physical Review Research 2 (3), 033010.
(2) Quantum Key Distribution Protocol Based on Contextuality monogamy, J Singh, K Bharti, Arvind, Physical Review A 95 (6), 062333.
(1) Revisiting the Admissibility of Noncontextual Hidden Variable Models in Quantum Mechanics, AS Arora, K Bharti, Arvind, Physics Letters A 383 (9), 833-837.
*: Equal contribution
Commentaries
(1) Fisher Information: A Crucial Tool for NISQ Research, K Bharti, Quantum Views 5, 61.