The Fractional Quantum Hall Effect and Gravity: A Copernican View C. S. Unnikrishnan Gravitation Lab, Tata Institute of Fundamental Research, Homi Bhabha Road, Mumbai 400005, India E-mail address: unni@tifr.res.in Website: www.tifr.res.in/~filab QIPA@HRI, 12 Dec. 2015 Core Idea and Plan All Physical phenomena happens in the gravitational presence of the entire matter-energy of the universe. Mass-energy being the charge of gravity and spin its current ALL physical phenomena that directly involves mass and spin are in fact causally gravitational, without exception . In particular, several quantum phenomena of microscopic physics are affected and often controlled by cosmic gravity. I seek to solve the mysteries of fractional quantum Hall effect within this paradigm (Cosmic Relativity). 1) 2) 3) 4) The Quantum Hall Effect and its explanation The Fractional Quantum Hall Effect and attempts for its explanation Key Experimental results relevant for this talk Composite Fermions, a mysterious gauge field and FQHE a) b) c) d) The Cosmic Relativity Paradigm Some established results Spin-gravity interactions The cosmic gravitational potentials and a real ‘gauge’ field FQHE as a QM phenomena in the combined vector potentials of electrodynamics and Cosmic gravity! QIPA@HRI, 12 Dec. 2015 Hall Effects QIPA@HRI, 12 Dec. 2015 Hall Effects (EN LABO) Larmour frequency: W = eB / m r = N / A, n = B / f0 = eB / h, n º r / n f0 e2 RH = 2 = ; s xy = n h ne ne h QIPA@HRI, 12 Dec. 2015 One electron per flux quantum fills the LL (Single free particle description) QIPA@HRI, 12 Dec. 2015 QIPA@HRI, 12 Dec. 2015 Fractional Quantum Hall Effect j n= 2 pj ± 1 Understood partially as a complex phenomena in a strongly interacting and strongly correlated system! Coulomb interaction dominate, collective effects are invoked, multi-particle relative phases are crucial…, and iteartive and heirarchical application of these effects are required. Also, fractional charges... f0 RH = 2 = ne ne h QIPA@HRI, 12 Dec. 2015 QIPA@HRI, 12 Dec. 2015 Quantum Hall Effect The entire phenomena can be measured in a single sample by varying the magnetic field or carrier density (hence varying filling factor smoothly) The QHE is understood as a singe particle effect and interactions can be ignored…Then why does one need a complex description with interactions and multiparticle effects for FQHE? Need a Copernican view! QIPA@HRI, 12 Dec. 2015 The necessary paradigm change QIPA@HRI, 12 Dec. 2015 300 Million Light years (up to Coma) 11 12 1 10 2 3 9 8 4 7 6 5 10 Billion Light years U All Galaxies QIPA@HRI, 12 Dec. 2015 G (4 R 2dR) / R 2 G R 2 H QIPA@HRI, 12 Dec. 2015 The universe is filled with gravitational charge at critical density. Just as an electrically charged matter density in the universe would have completely changed electrodynamics and Maxwell’s equations for moving particles (in comparison with an electrically neutral universe), Gravitationally Charged Universe hugely affects dynamics, relativity and all of physics, including the the theoretical description of gravity itself. QIPA@HRI, 12 Dec. 2015 If the distant universe were electrically charged, with homogeneity and isotropy, Maxwell’s equations will still be similar, without any experimental trace for uniformly moving charges… But wil give drastically different eperiment experimental results for accelerating and rotating charges. Ñ × E = r / e0 Ñ× E = - r / e 0 + r0 / e 0 ® f (r) + F0 ‘Maxwell’ would have invoked some electro-inertial pseudoforce (depends on e/m) to keep his equations and some Mach would have objected and asked look for a material source… QIPA@HRI, 12 Dec. 2015 1. Universe is gravitationally charged…and will hugely affect dynamics of anything with mass or energy, and spin, which is the current of the charge of gravity. 2. All physicall effects should be traced to physical interactions of real charges and currents of one of four fundamental interactions we have identified. In other words, there cannot be a real physical effect (change in energy, momentum, angular momentum etc.) without a real physical interaction. QIPA@HRI, 12 Dec. 2015 Moving through the Universe and its CMB marker Absolute velocity Absolute (universal) time Same as average T (1/105) Every observer can decide whether he is moving or not, and all clocks in the universe can be synchronized to this temperature. QIPA@HRI, 12 Dec. 2015 Universe with matter and radiation There is ONE special frame in which V=0 In all other frames, SPACE is anisotropic in the frame of a moving observer. There is a large current of matter (the charge of gravity) QIPA@HRI, 12 Dec. 2015 é g = -1 g = 0 0 0 00 01 ê 0 0 ê g10 = 0 g11 = 1 ê 0 g 21 = 0 g 22 = 1 0 ê ê 0 0 0 g33 = 1 ë ù ú ú ú + L(vr : x,t) ® ú ú û é g = -1 g = 0 0 0 00 01 ê 0 0 ê g10 = 0 g11 = 1 ê 0 g 21 = 0 g 22 = 1 0 ê ê 0 0 0 g33 = 1 ë ù ú ú ú ú ú û Isotropic space remains isotropic after Lorentz transformations on coordinates Clear conflict with real anisotropic space from matter current A physical and logically consistent boost transformation should have returned an anisotropic homogenous metric, reflecting the symmetry of the transformed space. QIPA@HRI, 12 Dec. 2015 ds = -dt + a (t){dx + dy + dz } 2 2 2 2 2 2 In a frame moving through this matter filled universe, there is a large matter-current and space is ANISOTROPIC x' = x -Vt, t ' = t ® é g ' = -(1- v 2 / c 2 ) g ' = v / c 0 0 00 01 ê ' ' g = v / c g =1 0 0 ê 10 11 ê ' ' 0 g = 0 g =1 0 21 22 ê ê 0 0 0 g33' = 1 ë ù ú ú ú ú ú û Galilean boost gives the physically consistent metric – flat and anisotropic QIPA@HRI, 12 Dec. 2015 gU 1017 m2 / s 2 gE 108 m2 / s2 300 Million Light years (up to Coma) 2 v 1 v2 2 1 c U 11 12 1 10 2 3 9 8 4 7 F gU » c ! 2 U 5 10 Billion Light years All Galaxies QIPA@HRI, 12 Dec. 2015 6 G (4 R 2dR) / R 2 G R 2 H Dynamics and Relativity from Cosmic Gravity (Cosmic Relativity) Principle of Relativity as unobservability of this ‘gauge’ potential. Same as statement of Lorentz/Galileo Invariance or invariance under boosts. NEWTON’S LAW FROM COSMIC GRAVITY It is already relativistic and ‘gravito-magnetic’ QIPA@HRI, 12 Dec. 2015 NEWTON’S LAW FROM COSMIC GRAVITY It is relativistic and ‘gravito-magnetic’ EQUIVALENCE PRINCIPLE FROM COSMIC GRAVITY If dynamics respects Newton’s law it respects Equivalence principle as well! C. S. Unnikrishnan, Int. Jl. Mod. Phys. (2014). QIPA@HRI, 12 Dec. 2015 Cosmic Gravito-magnetic Effects Universe in rotating frame Currents of mass generate large vector potential And its ‘curl’ is a strong gravito-magnetic field QIPA@HRI, 12 Dec. 2015 QIPA@HRI, 12 Dec. 2015 In the interferometer frame: Mass current with curl Gravitomagnetic field QIPA@HRI, 12 Dec. 2015 Atom Interferometer Gyroscope and Cosmic Gravity QIPA@HRI, 12 Dec. 2015 Current-current interaction (Ampere) in gravity Fg (i1,i2 ) = 4G 1 c2r c2r (mv) (mv) « F = 1 2 em 2 QIPA@HRI, 12 Dec. 2015 (ev) (ev) 1 2 2 Cosmic Gravity and Spin Physics SPIN (both classical and quantum) will couple to this because spin and angular momentum are currents of the charge of gravity – mass currents So, ALL spin-orbit effects (including second order effects) on neutral particles are due to gravitational interaction, coupled to the gravitational mass of the particle – there is no exception. Unnikrishnan: Relativity and Dynamics in the once-given Universe (in prep.) QIPA@HRI, 12 Dec. 2015 An Ampere Experiment in Electromagnetism Current-Current Interaction The flip of the magnetic moment is due to a reversed current-current interaction or reversed magnetic field, now written as QIPA@HRI, 12 Dec. 2015 An ‘Ampere Experiment’ in Gravity QIPA@HRI, 12 Dec. 2015 Unnikrishnan, General Theory of Relativity: The Universe between Beauty and Truth (ResearchGate) QIPA@HRI, 12 Dec. 2015 Several applications, insights and solutions… 1. Geometric phase on photon in helical fiber 2. Fine structure of atoms and Thomas precession 3. Spin-orbit energy splitting in chiral motion 4. Spin-transport in helical (bio) molecules 5. The spin-statistics connection 6. Fractional quantum Hall effect QIPA@HRI, 12 Dec. 2015 Spin-dependent geometric phase A. Tomita and R. Y. Chiao, PRL 1986 dj = 2ps (1- cosq ) QIPA@HRI, 12 Dec. 2015 R. Naaman, D. W. Waldeck, Ann. Rev. Phys. Chem. 2015 r ∼ 0.5 nm,v ∼ 5 ´10 m / s ® W ∼ 10 rad / s 5 15 s × Bg ∼ 1eV > kBT Gravity-controlled spin valve! QIPA@HRI, 12 Dec. 2015 Gravitational Vector potential as one moves around… QIPA@HRI, 12 Dec. 2015 QIPA@HRI, 12 Dec. 2015 Description in terms of a ‘composite fermion” (Jainendra Jain) CF=electron+ even number of flux quanta/vortices of a mysterious gauge field The FQHE is the IQHE of CF! QIPA@HRI, 12 Dec. 2015 The ‘flux’ associated with the electron cancels part of the applied magnetic field and reduced the degeneracy to the integer QHE level. QIPA@HRI, 12 Dec. 2015 D* = AB f0 * = D ∼ 2 pN j n= 2 pj ± 1 N n 1 2 n = = ® ( « 1, « 2...) D ∼ 2 pN 1∼ 2 pn 3 5 * QIPA@HRI, 12 Dec. 2015 QIPA@HRI, 12 Dec. 2015 Quantum Hall Effect The entire phenomena can be measured in a single sample by varying the magnetic field or carrier density (hence varying filling factor smoothly) The QHE is understood as a singe particle effect and interactions can be ignored…Then why does one need a complex description with interactions and multiparticle effects for FQHE? Need a Copernican view! QIPA@HRI, 12 Dec. 2015 QIPA@HRI, 12 Dec. 2015 1473-1543) QIPA@HRI, 12 Dec. 2015 Nilakantha Somayaji 1444-1545 (Tantrasangraha) QIPA@HRI, 12 Dec. 2015 Tycho Brahe (1546-1601) Gravitational Vector potential as one moves around… QIPA@HRI, 12 Dec. 2015 Bg = 2W = 2B(e / m) Since Aem = rB / 2, e Ag = rBg / 2 = - B(e / m) = -2 Aem m For LL with index n, Bg = 2nW, Ag = -2nAem (e / m) ® even number of flux lines! The extra ‘gauge field’ in FQHE is possibly gravity! QIPA@HRI, 12 Dec. 2015 We then need to establish the same coherent picture for the entire sequence QIPA@HRI, 12 Dec. 2015 Several remaining issues (in all theories of FQHE)… QIPA@HRI, 12 Dec. 2015 Summary: Cosmic Relativity, in which gravity of the matter-energy in the universe determines dynamics and relativistic effects, is the essential gravitational ingredient in classical and quantum dynamics. Several quantum phases conventionally described as spin-orbit phases are in fact cosmic gravitational phases (G,m etc.). This is confirmed in Thomas precession and the behaviour of photons and electrons in helical transport. The fractional quantum Hall effect has several features that indicate that cosmic gravity is indeed the extra field required for its single particle description. The pseudo composite-fermion is just a projected view, successful yet missing the true physics. However, several details need to be checked and matched and hopefully a more complete picture will emerge soon. QIPA@HRI, 12 Dec. 2015 QIPA@HRI, 12 Dec. 2015 QIPA@HRI, 12 Dec. 2015 QIPA@HRI, 12 Dec. 2015