Yury Bunkov

Yury (or Yuriy or Yuri) Mikhailovich Bunkov (Юрий Михайлович Буньков, 29 August 1950 in Stavropol) is a Russian experimental physicist, specializing in condensed matter physics. He is known as one of the co-discoverers of the quantum spin liquid state.

Education and career Bunkov, born into a family of geologists, graduated in 1968 from a special school for physics and mathematics in Moscow (School No. 2). In 1968 he also achieved first place in the Moscow Physics Olympiad and matriculated at the Moscow Institute of Physics and Technology (MIPT), which was headed by Piotr Kapitza.

According to Bunkov, should be called the "Bunkov echo":

In 1974 he matriculated at the Kapitza Institute for Physical Problems, where he received in 1979 his Candidate of Sciences degree (Ph.D.). was Bunkov's thesis advisor.

At the Kapitza Institute, he received in 1985 his Russian Doctor of Sciences degree (habilitation)

In the 3He-B phase (which has a complex phase structure) he experimentally discovered analogues to cosmological and quantum field theoretical phenomena, such as cosmological strings (as vortices in the spin supercurrent) and Majorana quasiparticles. In the 1980s he and his colleagues detected Goldstone modes (as phonons in the spin-superfluidity HPDs analogous to the second sound phenomena in superfluids). In the 2000s he discovered Q-balls] in superfluid 3He. (The concept of a Q-ball, a type of non-topological soliton, was originally introduced in quantum field theory.)

He collaborated extensively with the theorist Grigori Efimovich Volovik. In 2008, Bunkov and his Japanese colleagues discovered coherent precession in the helium-3-A phase embedded in uniaxially deformed anisotropic aerogels.

Bunkov is internationally recognized for his research on quantum fluids and solids, superfluid 3He nuclear magnetic resonance {NMR), and oltra-low temperatures techniques and their application to cosmology and the search for dark matter.

Bunkov received in 1993 the State Prize of the Russian Federation "for the discovery of magnetic superfluidity and the Homogeneously Precessing Domain". In 2001 Bunkov was made Doctor "Honoris Causa" by Pavol Jozef Šafárik University in Košice, Slovakia. In 2008 he was awarded, jointly with Vladimir Dmitriev and Igor A. Fomin, the Fritz London Memorial Prize for their discovery and elucidation of "unique phenomena in superfluid 3He-B: macroscopi phase-coherent spin precession and the flow of spin supercurrent." Bunkov has been a full member of the Academia Europaea since 2010.

Selected publications with A.S. Borovik-Romanov, V.V. Dmitriev, Yu.M. Mukharskiĭ: Long-lived induction signal in superfluid in 3-He, JETP Lett., vol. 40, no. 6, 1984, pp. 1033–1037 (translated by Dave Parsons) pdf with V.V. Dmitriev, Yu.M. Mukharskiy: Twist oscillations of homogeneous precession domain in 3He-B, JETP Lett., vol. 43, 1986, pp. 168–171. (Goldstone mode) with A. S. Borovik-Romanov: Spin supercurrent and magnetic relaxation in Helium-3, Harwood Academic Publ. 1990. with V.V.Dmitriev, Yu.M. Mukharskiy, Low frequency oscillations of the homogeneously precessing domain in 3He-B, Physica B, vol. 178, 1992, pp. 196–201. (Goldstone mode) Persistent signal; coherent NMR state trapped by orbital texture, J. Low Temp. Phys., vol. 138, 2005, pp. 753–758, (Q-Ball) with G.E. Volovik: Magnon condensation into a Q-ball in 3He-B, Phys. Rev. Lett., vol. 98, 2007, p. 265302. Spin Supercurrent, J. of Magnetism and Magnetic Materials (2007 article published in 2018). Arxiv 2007 with T. Sato, T. Kunimatsu, K. Izumina, A. Matsubara, M. Kubota, T. Mizusaki: Coherent precession of magnetization in the superfluid 3He A-phase, Phys. Rev. Lett., vol. 101, 2008, p. 055301. with G. E. Volovik: Bose-Einstein Condensation of Magnons in Superfluid 3He, J. Low Temperature Physics, vol. 150, 2008, pp. 135–144. with G.E. Volovik: Magnon BEC in superfluid 3He-A, JETP Lett., vol. 89, 2009, pp. 306–310. with G. E. Volovik: Magnon BEC and spin superfluidity: a 3He primer, Arxiv 2009 Spin superfluidity and magnons Bose-Einstein-Condensation, Physics Uspekhi, August 2010, Online with G. E. Volovik: Spin superfluidity and magnon BEC, in: Int. Ser. Monogr. Phys. 156, 2013, pp. 253–311, Arxiv with Rasul Gazizuzin: Observation of Majorana Quasiparticles Surface States in Superfluid 3He-B by Heat Capacity Measurements, Arxiv 2016 with Vladimir Safonov: Magnon Condensation and Spin Superfluidity, Arxiv 2017 with A. Farhutdinov. A. Kuzmichev, T. R. Safin, P. M. Vetoshko, V. I. Belotelov. and V. I. Tagirov: The magnonic superfluid droplet at room temperature. arXiv preprint arXiv:1911.03708 Arxiv 2019 Magnonic Superfluidity Versus Bose Condensation, Appl. Magn. Reson. vol. 51, 2020, pp. 1711–1721. with A. N. Kuzmichev, T. R. Safin, P. M. Vetoshko, V. I. Belotelov, and M. S. Tagirov: Quantum paradigm of the foldover magnetic resonance, Scientific Reports, vol. 11, no. 1, 2021, pp. 1–8.