1!

Chirality! from particles and nuclei to ! quantum materials ! !

D. Kharzeev !

RASA Conference, Cambridge MA, November 8-9, 2014 !

! What is Chirality?!

! Chirality, light, and matter!

! Chirality in nuclear and particle physics! example: Chiral Magnetic Effect (CME)!

! Chirality in quantum materials:! CME, optoelectronics, photonics, imaging!! example: precision surgical guidance in! cancer treatment!

Outline!

Chirality: the definition  

Lord Kelvin (1893): “I call any geometrical figure, or groups of points, chiral, and say it has chirality, if its image in a plane mirror, ideally realized, cannot be brought to coincide with itself.”!

Greek word: χειρ (cheir) - hand!

Chirality: DNA  

www.rowland.harvard.edu/rjf/fischer!

Living organisms contain almost only !left-handed (LH) amino-acids and right-handed (RH) sugars – !you would starve on LH sugar! (artificial sweeteners)!

2500 chiral drugs! (most of the new)!

Chirality: practical application, 240 B.C.!

6!The Archimedes screw!

Chirality and hydrodynamics, 300 million years ago !

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The Archimedes screw, Carboniferous period (360 - 300 million years ago) common in fossils; extinct since Triassic (250 million years ago)

Chirality: light and matter!

Louis Pasteur! 1822-1895!

Rotation of light polarization in!tartaric acid - absent in synthesized one,!but present in the one derived from!wine lees different mixtures of! left and right crystals !

Chirality in subatomic world: the neutrino!Only left-handed neutrinos!exist in the Standard Model!

Chirality and matter!Spin parallel to momentum:!right-handed!

Spin anti-parallel to momentum:!left-handed!

Chirality depends on !the reference frame:!

Chirality and matter!Chirality depends on the reference frame;!but, nothing can move faster than light!!!So for massless particles (moving with the speed!of light) chirality is conserved:!

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 Chiral particles!

non-relativistic,!massive!

massless,!relativistic!

nuclear physics, electrons!in solids, ...!

photons, neutrinos,!light quarks,!quasi-particles in chiral materials !

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 Chiral  par(cles  and  Dirac  sea  

E = ±p

m2c4 + p2c2

Chirality and light���

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Circularly polarized electromagnetic wave!can be left- or right-handed!!

Chirality and light, 2000 BC���

15!The scarab beetle – the symbol of !reincarnation in ancient Egypt!

Chirality and light

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Photographs of a scarab beetle (Potosia aeruginosa jousselini) taken through a left- and a right-handed circular polarizer, showing that the cuticle reflects !left-handed circularly polarized light!

Light and electromagnetism!

James C. Maxwell, 1831-1879!

Michael Faraday, 1791-1867!

Maxwell theory!is left-right !symmetric!

Chirality  in  electrodynamics:  Maxwell-­‐Chern-­‐Simons  theory  

Chiral current

Photons!DK, Annals Phys. 325 (2010) 205-218 !

Chiral Magnetic Effect:

chirality + magnetic field = current!

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spin!momentum!

DK,McLerran,!Warringa ‘07!

Chiral magnetic conductivity:discrete symmetries!

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P-even T-odd!

P-odd!

P-odd!

P-odd T-odd!

P-odd effect!!

T-even!

Non-dissipative current! (chiral electronics)!

cf Ohmic conductivity: T-odd, dissipative!

Effect persists in!hydrodynamics!!

P – parity (mirror)!T – time reversal!

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arXiv:1105.0385, PRL !CME on supercomputers!

The  Chiral  Magne9c  Wave:  oscilla9ons  of  electric  and  chiral  charges  

coupled  by  the  chiral  anomaly    

22!DK, H.-U. Yee, Phys Rev D’11

In strong magnetic field, CMW propagates with the speed of light!!

Chiral!

Electric!

Chirality in nuclear collisions: !experimental test!

LHC!

NICA, JINR Dubna!

Is there a way to observe chirality fluctuations in a nuclear experiment?!

Relativistic ions create!a strong magnetic field:!

H!

DK, McLerran, Warringa ‘07!

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Heavy ion collisions: the strongest magnetic field ever achieved in the laboratory!

+!

-!

excess of positive charge!

excess of negative charge!

Electric dipole moment due to chiral imbalance!

DK, Phys.Lett.B633(2006)260!

Charge asymmetry w.r.t. reaction plane as a signature of chirality!

NB: P-even quantity (strength of P-odd fluctuations)!

In Brookhaven Collider, Scientists Briefly Break a Law of Nature

By DENNIS OVERBYE Published: February 15, 2010

Physicists said Monday that they had whacked a tiny region of space with enough energy to briefly distort the laws of physics, providing the first laboratory demonstration of the kind of process that scientists suspect has shaped cosmic history.!

Quark Soup Physicists create conditions not seen since the big bang. Feb 16, 2010!

28!

Sharon Begley!

Scientists re-create high temperatures from Big Bang!

Hottest Temperature Ever Heads Science to Big Bang!

Atom smasher shows vacuum of space in a twist 17:27 15 February 2010 by Rachel Courtland!

The discovery of Dirac semimetals – 3D chiral materials!

Z.K.Liu et al., Science 343 p.864 (Feb 21, 2014)!

Ongoing experimental studies of Chiral Magnetic Effect!

Ongoing studies of CME in the Dirac semimetal Cd3As2!

T. Liang et al., 14014.7749!and to appear in Science !(September 2014)!!S. Jeon et al., !Nature Materials 13, !851–856 (2014)!

CME?!

Chiral electronics!

DK and H.Yee, Phys.Rev.B88(2013)115119;!G.Basar, DK and H.Yee, Phys.Rev.B89(2014)035142!

Practical applications of Chiral Magnetic Effect: sensors,!quantum amplifiers, generators, …!

Chirality at the tip of a pencil: graphene!

Graphene: single-atom-thick marvel!

Graphene:!from the lab to!industrial!production!

Graphene: new generation of electronic devices!

“Graphene is an impending turning point in high tech as important as silicon and integrated circuitry were half a century ago.” !

Why is graphene visible?!

Chirality in graphene  

E = v kMassless, chiral particles! strong coupling to light !

left! right!

v = 1/300 c!

Quantum tunneling of chiral particles  

Right-handed! Right-handed!

Left-handed!

Chirality !conservation!dictates 100%!wall penetration!!

Klein chiral tunneling  

O. Klein!1894-1977!

Klein tunneling in graphene  

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The goal: fight the power !dissipation using chirality!

Geim group, 2013!

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Ultra-fast, low-power!optical information!processing;!graphene-based!photonic circuits!

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Circularly polarized!photoluminiscence:!coupling of light to currents!

Right! Left!

T.Cao et al, Nature Comm 3 (2012) 887 !

Breaking the left-right symmetry!

Graphene  and  THz  radia9on  (T-­‐rays):    the  “last  fron9er”  in    

electromagne9c  spectrum  

non-ionizing!!

visible! THz!

THz  cancer  diagnos9cs  

SONY Corp and Tokyo University!

Squamos cell carcinoma ! of the lung ! Tumor!Tumor!

visible!

THz!

Graphene-­‐based  devices  for  THz  medical  imaging    

Integrated  medical  imaging  device  for  precision  surgical  guidance  

Cutting-edge science:fast and precise

THz surgical guidance !

S.Nakajima et al., Advanced navigation in!neurosurgery!

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Chirality  in  fundamental    and  applied  science  

Louis Pasteur!

There is no such thing as a special category of science called applied science; there is science and its applications, which are related to one another as the fruit is related to the tree that has borne it.