title: Ultrafast and reversible control of the exchange interaction in Mott insulators.
abstract: The strongest interaction between microscopic spins in magnetic materials is the exchange interaction Jex. Therefore, ultrafast control of Jex holds the promise to control spins on ultimately fast timescales. We demonstrate that time-periodic modulation of the electronic structure by electric fields can be used to reversibly control Jex on ultrafast timescales in extended antiferromagnetic Mott insulators. In the regime of weak driving strength, we find that Jex can be enhanced and reduced for frequencies below and above the Mott gap, respectively. Moreover, for strong driving strength, even the sign of Jex can be reversed and we show that this causes time reversal of the associated quantum spin dynamics. These results suggest wide applications, not only to control magnetism in condensed matter systems, for example, via the excitation of spin resonances, but also to assess fundamental questions concerning the reversibility of the quantum many-body dynamics in cold atom systems.
authors.affiliation: Max Planck Research Department for Structural Dynamics, University of Hamburg-CFEL, 22761 Hamburg, Germany.
authors.forename: J H
authors.initials: JH
authors.lastname: Mentink
authors.affiliation: Max Planck Research Department for Structural Dynamics, University of Hamburg-CFEL, 22761 Hamburg, Germany.
authors.forename: K
authors.initials: K
authors.lastname: Balzer
authors.affiliation: Max Planck Research Department for Structural Dynamics, University of Hamburg-CFEL, 22761 Hamburg, Germany.
authors.forename: M
authors.initials: M
authors.lastname: Eckstein
references.citation: Phys Rev Lett. 2003 Jun 20;90(24):247201
references.pmid: 12857221
references.citation: Phys Rev Lett. 2012 Jun 1;108(22):225304
references.pmid: 23003613
references.citation: Phys Rev Lett. 2012 Feb 3;108(5):057202
references.pmid: 22400955
references.citation: Science. 2010 Jul 30;329(5991):547-50
references.pmid: 20558666
references.citation: Phys Rev Lett. 2012 Aug 3;109(5):057401
references.pmid: 23006205
references.citation: Phys Rev Lett. 2013 Mar 22;110(12):126401
references.pmid: 25166823
references.citation: Science. 2013 Oct 25;342(6157):453-7
references.pmid: 24159040
references.citation: Phys Rev Lett. 2011 Jun 10;106(23):236401
references.pmid: 21770525
references.citation: Phys Rev Lett. 2011 Nov 18;107(21):210405
references.pmid: 22181863
references.citation: Phys Rev Lett. 1989 Jan 16;62(3):324-327
references.pmid: 10040203
references.citation: Phys Rev Lett. 2002 Oct 14;89(16):167402
references.pmid: 12398754
references.citation: Nature. 2013 Apr 4;496(7443):69-73
references.pmid: 23552945
references.citation: Nat Commun. 2013;4:1334
references.pmid: 23299884
references.citation: Phys Rev Lett. 2004 Nov 5;93(19):197403
references.pmid: 15600878
references.citation: Phys Rev Lett. 2014 Aug 1;113(5):057201
references.pmid: 25126933
references.citation: Phys Rev Lett. 2006 Apr 7;96(13):136801
references.pmid: 16712015
references.citation: Nature. 2012 Jan 25;481(7382):484-7
references.pmid: 22281597
references.citation: Nature. 2011 Apr 14;472(7342):205-8
references.pmid: 21451521
references.citation: J Phys Condens Matter. 2014 Sep 17;26(37):376001
references.pmid: 25156910
references.citation: Phys Rev Lett. 2000 Jun 19;84(25):5896-9
references.pmid: 10991082
references.citation: Phys Rev Lett. 2004 Sep 17;93(12):127201
references.pmid: 15447301
references.citation: Phys Rev Lett. 2007 May 25;98(21):217401
references.pmid: 17677804
references.citation: Phys Rev Lett. 2013 Mar 29;110(13):135704
references.pmid: 23581343
references.citation: Phys Rev Lett. 2015 Aug 14;115(7):075301
references.pmid: 26317726
references.citation: Phys Rev Lett. 1991 Jul 22;67(4):516-519
references.pmid: 10044914
references.citation: Phys Rev B Condens Matter. 1986 Sep 15;34(6):3625-3633
references.pmid: 9940124
references.citation: Phys Rev Lett. 2007 Nov 30;99(22):220403
references.pmid: 18233266
references.citation: Phys Rev Lett. 2009 Aug 28;103(9):097402
references.pmid: 19792828
references.citation: Phys Rev Lett. 2006 Dec 31;97(26):266408
references.pmid: 17280443