Quantum Computing
Optical qubits, coherent control of decoherence, and quantum algorithms
Optical approaches to qubits, coherent control of decoherence, and quantum algorithms using shaped femtosecond laser pulses.
The connection between coherent control and quantum computing is developed in detail in the review “Optical Pulse Shaping Approaches to Coherent Control” [1], a comprehensive Physics Reports article (approximately 100 pages) that devotes an entire section to quantum computing with shaped pulses. The review establishes that coherent control of molecular dynamics and quantum information processing share a common theoretical framework: both require steering quantum systems through desired state trajectories while suppressing decoherence.
The principal obstacle is decoherence: dephasing of quantum coherence through coupling to non-radiative channels. Minimizing decoherence is also the central challenge in quantum computing and quantum information processing.
Ensemble quantum computing with laser phase modulation
The 2002 Physical Review Letters paper demonstrated that laser phase modulation provides a viable route to ensemble quantum computing [2]. This was among the earliest proposals for using shaped femtosecond pulses as a physical substrate for quantum logic, treating molecular ensembles as qubit registers controlled through coherent optical fields. The accompanying theoretical framework showed that simple chirped pulses can control decoherence in quantum computing [3], and a dedicated review laid out the ultrafast pulse shaping approaches to quantum computing [4].
Adiabatic quantum computing
Building on this foundation, the lab developed an adiabatic approach to optical quantum computing. Phase-modulated laser pulses drive adiabatic passage through molecular energy landscapes, maintaining coherence throughout the computation [5,6]. Subsequent work probed the coherence aspects of adiabatic quantum computation [7] and assessed the practical feasibility of optical adiabatic schemes [8].
Molecular states as qubits
The foundations for this program were laid in the coherent control of multiphoton transitions with femtosecond pulse shaping [9], which demonstrated precise control over multi-level quantum systems. This naturally extended to using molecular ions and molecular states as physical qubits. Femtosecond control of molecular fragmentation with multiple control knobs (pulse shape, polarization, intensity) showed that molecular internal degrees of freedom can encode and process quantum information [10,11]. This all-optical approach avoids the cryogenic infrastructure required by superconducting or trapped-ion platforms.
Recent directions
More recent work addresses quantum distributed computing with shaped laser pulses and quantum algorithms [12,13,14].
Publications
Full list here.
- Optical Pulse Shaping Approaches to Coherent Control. D. Goswami, Physics Reports 374(6), 385–481 (2003)
BibTeX: @article{goswamiOpticalPulseShaping2003, title = {Optical Pulse Shaping Approaches to Coherent Control}, author = {Goswami, Debabrata}, year = {2003}, month = feb, journal = {Physics Reports}, volume = {374}, number = {6}, pages = {385--481}, issn = {0370-1573}, doi = {10/fwwrc5}, urldate = {2019-08-14}, annotation = {GSCC: 0000364 \\ 226 citations (Crossref) [2024-05-28]\\ 00000} } - Laser Phase Modulation Approaches towards Ensemble Quantum Computing. D. Goswami, Physical Review Letters 88(17), 177901 (2002)
BibTeX: @article{goswamiLaserPhaseModulation2002, title = {Laser {{Phase Modulation Approaches}} towards {{Ensemble Quantum Computing}}}, author = {Goswami, Debabrata}, year = {2002}, month = apr, journal = {Physical Review Letters}, volume = {88}, number = {17}, pages = {177901}, doi = {10/c339br}, urldate = {2019-08-14}, annotation = {GSCC: 0000040 \\ 22 citations (Crossref) [2024-05-28]\\ 00000} } - Decoherence Control in Quantum Computing with Simple Chirped Pulses. D. Goswami, Pramana 59(2), 235–242 (2002)
BibTeX: @article{goswamiDecoherenceControlQuantum2002, title = {Decoherence Control in Quantum Computing with Simple Chirped Pulses}, author = {Goswami, Debabrata}, year = {2002}, month = aug, journal = {Pramana}, volume = {59}, number = {2}, pages = {235--242}, issn = {0973-7111}, doi = {10/bv363m}, urldate = {2019-08-14}, langid = {english}, annotation = {GSCC: 0000001 \\ 0 citations (Crossref) [2024-05-28]\\ 00000} } - Ultrafast Pulse Shaping Approaches to Quantum Computing. D. Goswami, arXiv:quant-ph/0312192 (2003)
BibTeX: @article{goswamiUltrafastPulseShaping2003, title = {Ultrafast {{Pulse Shaping Approaches}} to {{Quantum Computing}}}, author = {Goswami, Debabrata}, year = {2003}, month = dec, journal = {arXiv:quant-ph/0312192}, eprint = {quant-ph/0312192}, urldate = {2019-08-14}, archiveprefix = {arXiv}, annotation = {GSCC: 0000018 \\ 00017} } - Adiabatic Quantum Computing with Phase Modulated Laser Pulses. D. Goswami, Journal of Physics A: Mathematical and General 38(38), L615–L626 (2005)
BibTeX: @article{goswamiAdiabaticQuantumComputing2005, title = {Adiabatic Quantum Computing with Phase Modulated Laser Pulses}, author = {Goswami, Debabrata}, year = {2005}, month = sep, journal = {Journal of Physics A: Mathematical and General}, volume = {38}, number = {38}, pages = {L615-L626}, issn = {0305-4470, 1361-6447}, doi = {10/cf95fb}, urldate = {2019-08-14}, langid = {english}, annotation = {GSCC: 0000010 \\ 7 citations (Crossref) [2024-05-28]\\ 00008} } - Adiabatic Quantum Computation: Coherent Control Back Action. D. Goswami, AIP Conference Proceedings 864(1), 273–294 (2006)
BibTeX: @article{goswamiAdiabaticQuantumComputation2006, title = {Adiabatic {{Quantum Computation}}: {{Coherent Control Back Action}}}, shorttitle = {Adiabatic {{Quantum Computation}}}, author = {Goswami, Debabrata}, year = {2006}, month = nov, journal = {AIP Conference Proceedings}, volume = {864}, number = {1}, pages = {273--294}, issn = {0094-243X}, doi = {10/dg98nw}, urldate = {2019-08-14}, annotation = {GSCC: 0000002 \\ 0 citations (Crossref) [2024-05-28]\\ 00002} } - Probing Coherence Aspects of Adiabatic Quantum Computation and Control. D. Goswami, The Journal of Chemical Physics 127(12), 124305 (2007)
BibTeX: @article{goswamiProbingCoherenceAspects2007, title = {Probing Coherence Aspects of Adiabatic Quantum Computation and Control}, author = {Goswami, Debabrata}, year = {2007}, month = sep, journal = {The Journal of Chemical Physics}, volume = {127}, number = {12}, pages = {124305}, issn = {0021-9606}, doi = {10.1063/1.2768954}, urldate = {2019-08-14}, annotation = {GSCC: 0000005 \\ 4 citations (Crossref) [2024-05-28]\\ 00005} } - On the Practicality of Adiabatic Quantum Computing with Optical Schemes. D. Goswami, International Journal of Quantum Information 05(01n02), 179–188 (2007)
BibTeX: @article{goswamiPracticalityAdiabaticQuantum2007, title = {On the Practicality of Adiabatic Quantum Computing with Optical Schemes}, author = {Goswami, Debabrata}, year = {2007}, month = feb, journal = {International Journal of Quantum Information}, volume = {05}, number = {01n02}, pages = {179--188}, issn = {0219-7499}, doi = {10/fkvv3x}, urldate = {2019-08-14}, annotation = {GSCC: 0000003 \\ 2 citations (Crossref) [2024-05-28]} } - Coherent Control of Multiphoton Transitions with Femtosecond Pulse Shaping. S. A. Hosseini and D. Goswami, Physical Review A 64(3), 033410 (2001)
BibTeX: @article{hosseiniCoherentControlMultiphoton2001, title = {Coherent Control of Multiphoton Transitions with Femtosecond Pulse Shaping}, author = {Hosseini, S. Abbas and Goswami, Debabrata}, year = {2001}, month = aug, journal = {Physical Review A}, volume = {64}, number = {3}, pages = {033410}, doi = {10/ffjx3v}, urldate = {2019-08-14}, annotation = {GSCC: 0000066 \\ 31 citations (Crossref) [2024-05-28]\\ 00000} } - Towards Using Molecular Ions as Qubits: Femtosecond Control of Molecular Fragmentation with Multiple Knobs. T. Goswami, D. K. Das, and D. Goswami, Pramana 75(6), 1065–1069 (2010)
BibTeX: @article{goswamiUsingMolecularIons2010, title = {Towards Using Molecular Ions as Qubits: {{Femtosecond}} Control of Molecular Fragmentation with Multiple Knobs}, shorttitle = {Towards Using Molecular Ions as Qubits}, author = {Goswami, Tapas and Das, Dipak K. and Goswami, Debabrata}, year = {2010}, month = dec, journal = {Pramana}, volume = {75}, number = {6}, pages = {1065--1069}, issn = {0973-7111}, doi = {10/cf945s}, urldate = {2019-08-14}, langid = {english}, annotation = {GSCC: 0000000 \\ 0 citations (Crossref) [2024-05-28]\\ 00000} } - Towards Using Molecular States as Qubits. D. Goswami, T. Goswami, S. K. K. Kumar, and D. K. Das, AIP Conference Proceedings 1384(1), 251–253 (2011)
BibTeX: @article{goswamiUsingMolecularStates2011, title = {Towards {{Using Molecular States}} as {{Qubits}}}, author = {Goswami, Debabrata and Goswami, Tapas and Kumar, S. K. Karthick and Das, Dipak K.}, year = {2011}, month = sep, journal = {AIP Conference Proceedings}, volume = {1384}, number = {1}, pages = {251--253}, issn = {0094-243X}, doi = {10/bfnp4m}, urldate = {2019-08-02}, annotation = {GSCC: 0000000 \\ 0 citations (Crossref) [2024-05-28]\\ 00000} } - Quantum Distributed Computing Applied to Grover’s Search Algorithm. D. Goswami, in Computing with New Resources: Essays Dedicated to Jozef Gruska on the Occasion of His 80th Birthday, C. S. Calude, R. Freivalds, and I. Kazuo, eds., Lecture Notes in Computer Science (Springer International Publishing, 2014), pp. 192–199
BibTeX: @incollection{goswamiQuantumDistributedComputing2014, title = {Quantum {{Distributed Computing Applied}} to {{Grover}}'s {{Search Algorithm}}}, booktitle = {Computing with {{New Resources}}: {{Essays Dedicated}} to {{Jozef Gruska}} on the {{Occasion}} of {{His}} 80th {{Birthday}}}, author = {Goswami, Debabrata}, editor = {Calude, Cristian S. and Freivalds, R{\=u}si{\c n}{\v s} and Kazuo, Iwama}, year = {2014}, series = {Lecture {{Notes}} in {{Computer Science}}}, pages = {192--199}, publisher = {Springer International Publishing}, address = {Cham}, urldate = {2019-08-02}, isbn = {978-3-319-13350-8}, langid = {english}, annotation = {GSCC: 0000004 \\ 00000 \\ 10.1007/978-3-319-13350-8\_14} } - Quantum Algorithm to Solve a Maze: Converting the Maze Problem into a Search Problem. N. Kumar and D. Goswami, arXiv:1312.4116 [quant-ph] (2013)
BibTeX: @article{kumarQuantumAlgorithmSolve2013, title = {Quantum {{Algorithm}} to {{Solve}} a {{Maze}}: {{Converting}} the {{Maze Problem}} into a {{Search Problem}}}, shorttitle = {Quantum {{Algorithm}} to {{Solve}} a {{Maze}}}, author = {Kumar, Niraj and Goswami, Debabrata}, year = {2013}, month = dec, journal = {arXiv:1312.4116 [quant-ph]}, eprint = {1312.4116}, primaryclass = {quant-ph}, urldate = {2019-08-02}, archiveprefix = {arXiv}, annotation = {GSCC: 0000007 \\ 00000} } - Quantum Distributed Computing with Shaped Laser Pulses. R. Goswami and D. Goswami, in 13th International Conference on Fiber Optics and Photonics (OSA, 2016), p. W4C.3
BibTeX: @inproceedings{goswamiQuantumDistributedComputing2016, title = {Quantum {{Distributed Computing}} with {{Shaped Laser Pulses}}}, booktitle = {13th {{International Conference}} on {{Fiber Optics}} and {{Photonics}}}, author = {Goswami, Rohit and Goswami, Debabrata}, year = {2016}, pages = {W4C.3}, publisher = {OSA}, address = {Kanpur}, doi = {10/gf5mrr}, urldate = {2019-08-01}, copyright = {All rights reserved}, isbn = {978-1-943580-22-4}, langid = {english}, annotation = {GSCC: 0000183 \\ 2 citations (Crossref) [2024-05-28]\\ 00000} }