I am an applied mathematician and a mathematical physicist. My current research is focused on quantum computation, complexity, and information theory. I also research the generic aspects of quantum matter, which convolves random matrix theory and free probability theory with quantum many-body systems. Every once in a while I foray into classical physics, chemistry, and engineering.

I am a permanent Research Staff Member in quantum theory and algorithms group (IBM Quantum) based at Yorktown Heights, NY. I work at the MIT-IBM AI Watson Research lab in Cambridge MA, USA. From 2015-2017, I was the Herman Goldstine Fellow in mathematics at IBM Yorktown Heights. In 2012-2015 I held postdoctoral positions at MIT, Northeastern University, and University of Chicago (with Leo P. Kadanoff).

I finished my Ph.D. in Mathematics at MIT in 2012 under the supervision of Peter W. Shor. At MIT I collaborated with Steven G. Johnson, Alan Edelman, Jeffrey Goldstone and Gil Strang. From 2005-2007 I was a research fellow (a “pre-doc”) at ETH-Zürich, where I worked on neuroscience and mathematical physics with Reinhard Nesper and Jürg Fröhlich respectively. I received my B.Sc. in 2004 in Applied and Engineering Physics from Cornell University, where I first started interacting with Roald Hoffmann.

How to *pronounce* my name: RAAmEEs Mov-**A**ss**A**

Erdös Number: 3

Einstein Number: 4

*I have a *blog *which is mostly of expository nature related to my research*

**Publications:**

**44.**(with M. Szegedy and G. Wang) “Repeated Averages on Graphs” arXiv: 2205.04535 (2022)

**43.**(with R. Andrei and M. Lemm) “The spin-one Motzkin chain is gapped for any area weight ” arXiv:2204.04517 (2022)

**42.**(with N. Harle and O. Shtanko) “Observing and braiding topological Majorana modes on programmable quantum simulators” arXiv:2203.15083 (2022)

**41.**(with O. Shtanko) “Algorithms for Gibbs state preparation on noiseless and noisy random quantum circuits” arXiv:2112.14688 [quant-ph] (2021)

**40.**(with L. Chen) “Quantum Merkle trees” arXiv:2112.14317 [quant-ph] (2021)

**39.**(with Y. Kondo and R. Mori) “Quantum supremacy and hardness of estimating output probabilities of quantum circuits” arXiv:2102.01960 [quant-ph]

**38.**(with S. Bravyi, D. Gosset) “Classical algorithms for quantum mean values”

*Nature Physics (Jan. 2021)*

**37.**(with Y. Ouyang) “Constructing quantum codes from any classical code and their embedding in ground space of local Hamiltonians” arXiv:2012.01453 [quant-ph] (2020),

**QIP-2021 video**

**36.**(with J. Schenker) “Theory of ergodic quantum processes” arXiv: 2004.14397 (2020)

**35.**(with O. Shtanko) “Unitary subharmonic response and floquet Majorana modes,” arXiv:1911.05795.

*Phys. Rev. Lett.*

**125**, 086804 (2020)**34.**(with J. Schenker) “An ergodic theorem for homogeneously distributed quantum channels with applications to matrix product states ” arXiv: 1909.11769 (2019)

**33.**(with J. Gambetta, A. Mezzacapo, P.K. Temme) “Cost function deformation in quantum approximate optimization” U.S. Patent No. 10,452,990. 22 Oct. 2019.

**32.**“Quantum Supremacy and random circuits”, arXiv: 1909.06210,

**QIP-2020 video**(2019),

**Featured in American Physical Society News Feb. 18., 2020**

**Era of quantum supremacy**

**31.**“Efficient unitary paths and quantum computational supremacy: A proof of average-case hardness of Random Circuit Sampling”, arXiv: 1810.04681

**29.**(with J. Michel, S. Reddy, R. Shah, and S. Silwal) “Directed Random Geometric Graphs,” arXiv: 1808.02046.

**28.**Y. Tsuji, E. Estrada, R. Movassagh, and R. Hoffmann “Quantum Interference, Graphs, Walks, and Polynomials,”

*arXiv:1804.09234.*

**27.**“The gap of Fredkin quantum spin chain is polynomially small,” arXiv: 1609.09160,

**26.**“Generic local Hamiltonians are gapless,”

*arXiv:1606.09313.*

**25.**

**“Entanglement and correlation functions of the quantum Motzkin spin-chain,”**

*arXiv: 1602.07761.*

*Journal of Mathematical Physics 58, 031901 (2017),*

**24.**(with L. Levine) “The gap of the area-weighted Motzkin spin chain is exponentially small”

*J Phys. A: Math. Theor. 50 255302 (2017),*arXiv: 1611.03147

**23.**(with G. Strang, Y. Tsuji, R. Hoffmann), “The Green’s Function for the H{\”u}ckel (Tight Binding) Model,” arXiv: 1407.4780

**22.**(with A. Edelman), “Eigenvalue approximation of sums of Hermitian matrices from eigenvector localization/delocalization” arXiv:1710.09400 (2017),

**21.**(with L. P. Kadanoff), “Eigenpairs of Toeplitz and disordered Toeplitz matrices with a Fisher-Hartwig symbol,”

*arXiv: 1604.08295*

**20.**(with Peter W. Shor) “Supercritical entanglement in local systems: Counterexample to the area law for quantum matter,”

*arXiv: 1408.1657*

*Proceedings of the National Academy of Sciences: p. 201605716 (Nov. 7, 2016)*

**QIP-15 video,**

*[KITP video],*

**Featured in MIT News Nov. 18., 2016.**Entanglement bonanza

**19.**“Eigenvalue attraction,” arXiv: 1404.4113

**18.**(with E. Cuervo-Reyes) “Non-affine geometrization can lead to nonphysical instabilities”

*J. Phys. A: Math. Theor. 48, 075101 (2015)*

**,**

**Featured on the Cover of issue 7, volume 48**

**17.**Y. Tsuji, R. Movassagh , S. Datta, and R. Hoffmann “Exponential Attenuation of Through-Bond Transmission in a Polyene: Theory and Potential Realizations”

**16.**(with L. Chang, M. Cheng, S. Cui, Y. Hu, W. Jin, P. Naaijkens, Z. Wang, A. Young) “On Enriching the Levin-Wen Model with Symmetry,”

*arXiv: 1412.6589*

**15.**Y. Tsuji, R. Hoffmann, R. Movassagh and S. Datta “Quantum Interference in Polyenes”

*The Journal of Chem. Phys. 141, 224311 (2014)*

*Phys. Rev. A 88, 023829 (2013)*

**Editor’s suggestion. Featured in MIT Tech Review .**

**13.**(with M. Coudron) “Unfrustration condition and degeneracy of qudits on trees”

*arXiv:1209.4395,*

*(2013)*

**12.**(with A. Edelman), “Condition numbers of indefinite rank-2 ghost wishart matrices,”

*arXiv: 1207.3062*

**11.**(with S. Bravyi, L. Caha, , D. Nagaj, P.W. Shor), “Criticality without frustration for quantum spin-1 chains,”

*arXiv: 1203.5801*

*Phys. Rev. Lett. 109, 207202 (2012)*,

**Featured in MIT News. Nov. 27, 2012,**

**10.**(with J. Chen, A. Edelman, E. Hontz, J. Moix, A. Surez, M. Welborn, T. Van Voorhis) “Error analysis of free probability approximations to the density of states of disordered systems,” arXiv: 1202.5839

**Featured in MIT News June 22, 2012, Space Mart, Science Daily.**

**9.**(with A. Edelman), “Density of states of quantum spin systems from isotropic entanglement”

*Phys. Rev. Lett. 107, 097205 (2011)*

**QIP-11 video**

**8.**“A time-asymmetric process in central force scatterings” arXiv:1008.0875, (2010)

**6.**(with E. Farhi, J. Goldstone, D. Nagaj, T. Osborne, P.W. Shor) “Unfrustrated qudit chains and their ground states,” arXiv: 1001.1006

**5.**O.E. Rössler, D. Fröhlich, R. Movassagh and A. Moore, “Hubble-expansion in static space time”

*Chaos, Solitons and Fractals 33, 770-775 (2007)*

**4.**(with O.E. Rössler) “Bitemporal Sinai divergence: an energetic analog to Boltzmann’s entropy?”

*International Journal of Nonlinear Sciences and Numerical Simulation 6(4), 349-350 (2005)*

**3.**R. C. K. Wong, L. G. Ko and R. Movassagh “A study of flow tortuosity in locked oil sand”

*Canadian Journal of Petroleum and Technology Volume 43, Issue 1 (2004)*

**Refereed Conference Proceedings**

**Refereed Conference Proceedings**

**2.**C. Richmond, R. Geddes, R. Movassagh, A. Edelman, “Performance of sample covariance based capon bearing only tracker”, IEEE 45th Asilomar Conference on Signals, Systems and Computers, Nov. 7 10 (2011)

**1.**C. Richmond, R. Geddes, R. Movassagh, A. Edelman, “Sample covariance based estimation of capon algorithm error probabilities”, IEEE 44th Asilomar Conference on Signals, Systems and Computers, Nov. 7 10 (2010)